Not as strong as I once believed....

I’ve been with my husband for almost 7 years, since I was 16. I told myself if he ever was unfaithful I would leave him, well the day came a few years ago where I found out he was unfaithful and I couldn’t leave, I stayed like a dumbass. I am way too attached to him, I am extremely in love with him and I hate myself for it. He has continued to be unfaithful and I’ve confronted him but still stayed. I can’t get myself to leave him there is too much history and attachment. He tells me we should end it because there is too much damage done but I don’t want to be without him. I know I deserve better I want to be happy and move on but to see him with someone else kills me. I also don’t have any family or friends I could go stay with, we also have a 5 year old. He has ripped my heart to shreds and lies like he’s so faithful. He has a private fb account he doesn’t think I know about (I can’t seem to get into it) and talks to women. I am already experiencing heartache I literally cry everyday and he sees me cry but doesn’t change. Why am i not good enough? Ugh.