My boyfriend left me because of how i changed after a traumatic head njury, in fairness he did stand by me?

through the worst of it. Quite a few of my friends have picked fights with me and our now refusing to talk to me too. it wasn't my fault and I really just want my life back the way it was before. I was happy then. Even after i was building my future with him now he has gone I feel like i have nothing to live for. How can I be happy again. I didn't want the accident or the problems it has given me.