It's not me, right?? Should I stay or go?

Hi!  I'm new here, and while I have learned A LOT so far (the books have helped me to feel like I was able to decode a language I couldn't speak before), I am stuck in trying to decide what to do.  I apologize in advance for the length of this post - believe it or not, it's the short version!  Lol

Am engaged to, and living with, my ADHD partner.  He's 55, I'm 47.  We met 4 yrs ago, got involved 3 yrs ago, and have lived together for 1.5 yrs.  Got engaged last fall.  I found him exciting, energetic & very helpful around the house, fixing things, etc.  I knew he was ADHD and started to educate him on it.  I couldn't believe he had managed to get through his life without knowing he was ADHD.   He was on worker's comp due to injury but he was so aggravated he couldn't work, I thought for sure he'd get a job as soon as he could.  When I met him 3 years ago, he was in the process of ending a LTR of 20+ yrs.  She was abusive, both physically & emotionally - very manipulative, and a meth addict & alcoholic.  He gave her the house and she lost it  within months due to her addiction.   I offered up MY house to 2 of his 3 adult kids (the 3rd is older, married, and on her own), because I felt bad that the kids were stuck in such an awful situation at such a young age (23 and 19).  He then got a dog (going against my plea to NOT get one).  I love the dog, but I did not want one in my life.  I had grown up with dogs and know the responsibility that comes with them, and I didn't want it.  I had spent the last 20 yrs as a single parent working 2 jobs and going to school.  Now that my son was grown, I wanted to FINALLY enjoy my life - travel, etc.  Anyway, the level of chaos in my life went from 0 to 100 in no time. Within months, we found out the kids had used & manipulated us, and betrayed him by telling his ex information she felt she could use against him in the divorce.  My own son (20) moved out bc he couldn't deal with the chaos.  Both his kids were asked to leave, and I was outraged.  Feeling like I had been blindsided and walked over.  Why didn't he tell me his kids were like this?  Prob bc I never would have let them live with us.  The dog turned out to have a host of medical problems, costing me close to $5000 for surgery and meds and followup appts.   Fast forward to the present, and it's still the same problems - he doesn't have a job, kids have bounced from house to house, can't keep a job or finish school, and continue to use and manipulate whoever comes in their path.  After dealing with this drama for years, I finally set up some boundaries - and told him if he asked for either of his kids to live with me again, I would simply say No, and would ask him to leave as well.  The level of disrespect from them is astounding!  I am just now starting to realize the lack of respect I receive from him as well - I pay for EVERYTHING, including his entire family's cell phone bill, my mortgage & bills, etc.  He was supposed to be giving me between $600 - $800/mo.  I pay over $3000/ month.  I rarely receive anything.  For over a year, we fought constantly about how MY NEEDS were NEVER being met.  My credit has been destroyed, there is no food in the house, and I have to count pennies to put gas in my car to get to work.  I have numerous health problems of my own that were previously controlled but are now starting to come back because I haven't been able to afford the proper food, supplements, or medical care for myself as it's been ALL ABOUT HIM since he moved in.  He apologizes constantly.  It used to matter.  Now I just feel he is scrambling bc he doesn't want me to ask him to leave. 

I've worked REALLY hard to get what I have in life.  To get an education, to get my own health problems figured out, to repair/maintain good credit, to get a great job, and own a house.  I have "gone without" for years, and was looking forward to this time in my life when I could be free from the responsibility of having to raise my son, etc.  Instead of traveling and doing new things, we sit at home and watch tv.  He is addicted to marijuana, claims it helps his ADHD (and it does, but so do many other LEGAL drugs).  After doing some research and realizing a LOT of his issues stem from his ADHD,  he said he would get help as well as counseling to deal with the anger issues from a rotten, abusive childhood and over attachment issues he has to his daughter.  He has yet to even look into it.  I question if he is even capable of doing it.  In fact, I am questioning EVERYTHING.  I feel used, and manipulated.  I am exhausted, and my work is suffering.  It is ALWAYS about him & his problems.  I do ALL the reading, the research, etc for any of his health conditions.

To my family & friends, the writing is on the wall.  But for myself, I am having a hard time asking him to leave.  He doesn't have the tools he needs to control his ADHD and have a decent life.  He cannot save money to save his life.  He does not have the capability to contemplate and plan for retirement.  He couldn't create a resume because he couldn't remember where/when he has worked over his life, but I found that if he dictated it to me, he could.  Is that manipulation or a learning disability associated with the ADHD?  And why is it always ME that searches for the answers - it's like he doesn't care to learn about himself/fiz the problems that hold him back.  i question if he even realizes it holds him back!.

Do I ask him to leave?  I do love him, but I feel like I need much more in my life (primarily peace and quiet with no drama!!!!).  Do I wait until he gets a job/gets ADHD help/coach/dr/meds or will this most likely never actually happen? 

I'm so lost, hurt, depressed & confused! :-(