I Feel Like I Am Never Good Enough

The reason I don't feel good enough us that I see that she dated jerks who broke her heart and every time I helped her I even beat up my best friend because he broke up with her and every time she has feelings for people who leave her even now the latest one left her to go into a relationship with her friend and when I met her she said the guy who she dated 3 years ago still remembers me after getting drunk and all I mean like she sees all that and tell that but doesn't she see I've been there by her side and making her happy and making her feel special and loved for 6 years that's the thing that hurts me. Then she says when did I hurt you, she didn't but this thing what I see that hurts me and I don't tell it to anyone but it hurts me deep inside I feel like I'm not good enough even though I'm not like those jerks and idiots who just left her in the dump. That's why I sometimes feel like she doesn't value me or probably I don't deserve her but if I say that I'll never break her heart and her trust then is it gonna harm someone to try and understand someone instead of just hearing stories of her ex boyfriends remembering her who dumped her and now remember her but I want to ask her don't you see I never tried to hurt you and I always wanted you to be happy then why am I not good enough .Just makes me feel stupid sometimes