Am i the asshole for braking up with my bf?

Where to start? We met 3 years ago and quickly became a cupel. I was, and still am, struggling with anxiety and depression and he knew from the start. Stil he didn’t do anything to make my life easier. If I started crying I was a drama queen, and if I asked him to stop doing something, like stop swearing, he accused me of trying to censor him in his one house. 
When I was better at him in something he would also get angry. Like if I got a better grade than him he would say I didn’t deserve it, and that he worked so much harder than me. 
Now I have low self esteem. And he often had me on the edge. Braking up whit me and than taking me back whit-in hours. 
When he found out I had started to think about leaving he said he would kill him self if we broke up. That terrified me and so every time I went to stay with my mom I quickly returned in fear of him having hurt himself.
Then he told me he was transsexual. He wanted to become a woman.  
A had known him for years and know this...
The following months he became more and more unstable, and I urged him to get help. To talk to someone professional. But even though he eventually did, I was still being his therapist at home.
Having my one problems it all became to much. And whit a lot of help I was able to move home. 
We cut all contact for a few months and when I talked to him again it came out that he had attempted suicide four times. We had contact for a while after that. Trying to find out if we could save it. But after several nights of him pressuring me in bed it became to uncomfortable. I left once again. 
Know I feel awful. Like I have let him down. He is going through, not only working through the memories of a difficult childhood. But also working his way towards a sex change. 
Its all just to much.