What is fair?

Hello.  I so appreciate this forum.  Now more than ever.  My husband of almost 19 years does not have ADD, I do.  (Quick funny story: about 18 years ago I tuned into an Oprah show about adult ADD.  I was convinced my husband had this.  But as I watched I realized they were describing everything about me.)  Anyway... H (husband) and I have been separated since 9/10 (but had been living in the same house up until 8/11).  We have 3 kids.  Our oldest will be 18 in a couple of weeks.  He has ADD + mood disorder (mostly depression) + asperger trait's.  He has been at a wonderful therapeutic boarding school (since ~ June '11) waaayyyy out near the west coast and near Canada, we live on the east coast.  Before he went there we sent him to a very loving and nurturing wilderness program in GA last March ('11) and after ~90 days on his last night H and I flew out there to spend the night in the woods with our son.  The next day we all flew out to where he is now.  The day we flew out, just H and I, to stay with our son on his last night in the woods, we sent our 13 year old daughter (AD*H*D-she's VERY energetic) out to CA on an Outward Bound backpacking expedition for kids (boys and girls) her age with the same kind of issues.  Her issues had been lying, emotional outbursts (just with me), and obsessive about boys.  I was concerned about her lack of sense of self, because her boyfriends were her "life".  And we "forbade" her from having a boyfriend because she was too young.  (Reality, H "forbade" it, I did not approve of her having a boyfriend, but it was happening anyway and I wanted her to feel like she could talk about it without being scared of punishment.)  And we have a 7 year old daughter, no noticeable AD/HD symptom's yet, though, the older 2 were "officially" diagnosed when they were ~8-9 years old, but they had symptom's way before.  MY POINT... We have A LOT of challenges.  I work full time weekend shifts, I'm an RN in a NICU (Neonatal ICU- premature and sick newborn babies).  I've been a nurse for >13 years, 10 of those in the NICU at the same hospital.  I do take Prozac and Vyvanse (140mg/day).  I suck at budgeting, organization/cleaning, being consistent, the usual classic ADD stuff.  I'm also very proactive in finding ways to manage my world.  H has been so supportive and patient up until he started a retail business about 3 years ago.  His store is 40 minutes away and he's gone from 7:30ish in the morning to 7:30/8ish at night.  Before that he had a home inspection business and his time was incomparably more flexible.  In other words, he was around to help out more with things around the house and with the kids.  I felt like I had become a single parent when he opened his store.  Shall I summarize??  We had gotten caught in that viscous circle of hopelessness, anger, resentment, etc.  H felt hopeless because I stopped listening and talking with him.  I stopped doing those things because I didn't feel it made a difference and every time I said anything or did anything I got put down and blamed for creating ALL of the chaos.  I truly do understand H's perspective.  I couldn't really "get it" though, until he left to live with his mom this past August.  (He took our 13 y.o. with him because I wasn't able to provide enough structure for her (and other, very complicated reasons).  I was RELIEVED when he left.  I didn't have to worry about what he was going to berate me for next.  I honestly though at times H had a brain tumor because his behavior and the way he treated me was so uncharacteristic.  H has enormous integrity.  When he left, I was ok with it.  I didn't want him to be unhappy and I didn't want him making me unhappy.  I literally said to him, "I love you very much, it's ok if you want to go."  He really didn't want to go, he just wanted me to change.  I took offense with that, sort-of.  The things he wanted me to change were the same things I wanted to change about myself.  And I did put in the effort, but it wasn't enough and it wasn't instantaneous AND I wasn't consistent (go figure).  So, at the beginning of our year+ long  separation, I'm doing the "single parent" thing (WITH AD/HD ADOLESCENTS), my brother tried to commit suicide (way too complicated to get into) and I'm the ONLY person nearby to be there for him, and my mother gets diagnosed with pancreatic cancer (she is a 2 time breast cancer survivor).  She lives 2 hours away, and I had to take her to doctors appointments quite often and get back home in time to pick the kids up from school.  Did I mention what my work hours on the weekends are?  No?  Oh, well, I work EVERY SINGLE SATURDAY AND SUNDAY 12 HOUR SHIFTS (7AM-7PM) AND EVERY SINGLE MONDAY NIGHT SHIFT (11PM-7AM).  I'm thinking to myself I doing an amazing job considering my brain DISABILITY.  (Let's call a spade a spade, People.)  But, H's resentment had been building and building.  Yes, I did spend way too much money.  According H, I nearly put him out of business and in jail (he wasn't able to pay employee taxes).  I do not mean to justify that in any way, I take 100% responsibility for my poop, BUT the things I bought were for the kids and a lot was from groceries and eating out.  I have expressed how truly sorry I am.  No, I didn't listen to H telling me to "Stop spending money", "you have to stay in the budget"...."blah, blah, blah".  We learned within the first year of our marriage (before my ADD diagnosis) that "balancing the budget" was not a skill I possessed.  H is very skilled at it, but he is also very anxious about spending money.  He is very much a saver.  (My 1+ carot diamond engagement ring was paid for with PENNIES he had saved.)  This is NOT an excuse, but I know even people without this brain disability can relate to how exhausted and stressed out I was.  I hate making dinner as it is, the hardest part is just figuring out what to make, right?  I'm schlepin here and there, and buying food on the run adds up.   Are you still with me?  Sorry this is so long.  Please bear with me a little more, thank you so much.  The other thing that drove H crazy was me being on the computer.  ALL THE TIME.   It's true.  I retreated into the portal of infinite information.  (BTW: my Meyers Briggs is INTJ, I love learning and thinking.)   I stayed up way too late, sometimes all night, 'Googling' stuff about "How to Budget" or "AD/HD in parents who have kids with AD/HD" or "Why does my husband hate me?"  Ok, so, I "get it".        H wants a partner.   I hadn't made our relationship a priority.  He was convinced I wasn't capable of changing and I just wanted him to accept me for who I was.  Counseling, you ask?  OMG, YES!  AS a matter of fact, H would say, "we've been to counselor after counselor, and I see some changes, but it always goes back."  I'm like F-U, Jerk.  (No, I didn't say that for real.)  So, I'm all for ending our marriage and thankfully, he agreed to do it collaboratively (google-collaborative divorce).  After our first meeting with our collaborative lawyers, I had this HUGE paradigm shift in my perspective.  I did not want to divorce.  I totally do not think it is necessary.  I was soaking up audio books left and right.  I listened to Steven Covey's "7 Habits...,"  Ned Hallowell anything, Dr. Ari Tuckman's podcasts, on and on.  I was finally understanding my brain disability like I never had before.  I REALLY GOT IT!!!  So, I informed H and our lawyers and the whole collaborative team that I didn't want to divorce.  H had started to see an "old friend" (we'll call her S) already.  I was devastated.     But, he said he still loved me.  I've come to understand he is terrified that I'm not going to be there for him.  And he doesn't want to keep "going through cycles" of me make good changes and then "slacking" off.   I get that.   He wants to continue with our divorce.  I want to shake him and tell him how stupid he's being.  I don't want to lose him.  We both know each other better than ourselves.   And we both love each other.  But he's not convinced I've changed.  Isn't it only fair that he give me a chance to show him?  He was willing to before he started seeing S.  Mind you, S divorced the year before and she's a fresh empty nester, so I'm sure she is more than willing to lick his wounds.  (In case you're wondering, I'm 40 and H and S are the same age, 51.  So, no she is not younger.)  I don't know if I can let this go.  I believe in commitment, our commitment.  Divorce is not acceptable to me.  I feel like I'm trying to prevent a tragedy from happening.  Thank you for reading.   <3