Feeling like a monster in my relationship

I feel like a monster. I feel like I’m a horrible partner to my fiancé. And I don’t pay enough attention to them, and that they don’t pay enough attention to me. I just feel like an attention whore and I feel terrible. I expect so much from my partner but don’t do enough in return. I don’t know how to stop myself from being a horrible person. I feel uncontrollable. I can’t blame anyone else, but me - It’s not another alter.