Hi @Tornup, I'm sorry you're in such a difficult spot. I agree with what @Ainjoule suggested as I have similar issues with my partner due to low self esteem. I don't actively try to push her away, but I do keep a lot to myself and I know it frustrates her when she knows i'm not coping well.
I have the same thoughts about not deserving her and that she would be better off with someone better than me. But I keep telling myself, that's she been there supporting me for this long and not left me so maybe I just need to trust a bit more and learn to let he in a lot more. Accept that she loves me and wants to help. One of the big things I've learnt from using support groups the past 12 months or so is that I do judge myself way harsher than everyone else does and that I need to be kinder to myself in order to let people support me. It seems to be that if your partner is still trying, then he is trying very hard to be supportive and to be there for you, so maybe, like me, you just need to learn to let him and take it a bit easier on yourself.