To separate or not separate. Help! :)

My Husband and I have been married for 15 years.  We have two young kids.  Within the last year or so he has finally agreed to medication and learning about his ADHD which he was diagnosed with as a child and never dealt with.  I have decided that if things don't change that I can no longer stay married to him. I have completely met my breaking point.  I now have depression, severe anxiety, stomach problems, withdrawing from friends and family and am constantly in fight or flight mode. I feel that I have given everything to my marriage and do truly love my husband but I can't deal with things anymore the way they are.  I was out of town all week and after a year of messing with his medicine he finally feels like he might have the right combination.  My husband has read Melissa's book, worked on his relationship with our kids and devoted time and energy to getting better.  Seems like we have had a great week as we talk on the phone and check in with each other.  At first I was really excited feeling ready to come home and work on things with him. However now I am terrified as I realize that I can't live the wat we have been and maybe I am setting us both up for failure by living together right now.  I know that I can't expect him to change overnight but I am also desperate to take care of my own mental and physical health.  I am wondering if it would be good to live separately for a little while until I have time to live in some peace, therapy and heal myself and he has some time to develop more skills to help himself. He is completely dependent on me for everything and we did try one week apart but that seemed to go well so I let him move back in. He was devastated about moving out for that one week. And his first night home we got in a big fight and then I left to go out of town.  I need help.  Separation while we work on ourselves or stick it out together hoping desperately things will get better soon.