I Don't Know What to Do Anymore

My boyfriend had an accident and is now confined in a wheel chair and ever since his personality has split. He turned into a monster! He yells, became increasingly aggressive, verbally abusive and is very manipulative and can't keep a proper conversation without being aggravated.I empathize with him and find it hard to leave him because I know what a great person he was, to make it worse he refuse to seek therapy or counselling. This whole thing is stressing me and I feel stuck