I don’t know what’s wrong with me

I have always been depressed but it’s not constant, I have good days and bad days sometimes I find myself crying for no reason and thinking bad thoughts when I was just having a great time, I always worry and I am self conscious and cannot trust my boyfriend even though he is perfect, I realized my issues but I cannot fix them. I need help but my doctor always suggests therapy which I do not want to do I think it’s useless. It’s tearing my relationship apart and he wants to move forward but I’m the one holding us back, I know he deserves better than me I want to make myself better for him and for me