Wonderingalways…….When he tells you that "my brain works crazy because of my illness"....it sounds, to me, like he is acknowledging that he has problems in coping with reationships…...coupled with the fact that his longest relationship has been only 5 months....at his age.
those are important red flags, when you are dating someone.
The way he ended it is another evidence that he has trouble in navigating relatiosnhips with others.
What you see, with him, is probably just the tip of the iceberg in regard to his relationship issues.
While he may have some good features that you liked....some people are just good relationship material....they just don't have the necessary tools to maintain and nurture a realionship. He probably knows that....which is why he told you what he did.
It takes two healthy people to maintain a good relationship. If you are healthy, in that way, and he isn't...there is nothing you can do about that....
The best that you can do in that situation is to grieve the loss of your dream and go forward in life...…
What you are experiencing is, I think, grieving a great disappointment.
I suggest that you might read the most frequently recommended book on this forum..."Co-dependent No More". I think a lot of it will resonate with you. You can get it on amazon.com or at the local library. It is an easy read.....and, I think it will be consoling to you.....