I don’t know why I’m still in this relationship. Help!

I’m in a toxic relationship that just takes and takes from me. I am in therapy and my counselor really thinks I should leave and take care of myself because I have given my partner years of chances, only to be mistreated and forced to be his mother. He is codependent and I probably am too from a messed up childhood. I devoted my whole life to him and we have a house and were going to get married. I constantly sway between feeling like I could stay and feeling like things are really bad and I need to leave now. Please help. I feel so trapped and don’t know what to do!