<human>: Can you summarize the given text in a few sentences?

Our relationship has experienced infidelity from both partners, and we have always come clean about our mistakes. However I can tell that our past is eating away at the vitality of my SO, I have seen her trust in me get worse and dwindle. I know it is killing her even though it has been over a year since the last time either of us fucked up. 

I know she deserves someone better than me, but every time i bring it up she begs me to understand she forgives me and "doesnt care about any of that". I know its a lie. I cant bring myself to leave her, but Im starting to think it would be best for her. 

I am overcome with guilt. I know she feels guilty as well. My brain is fried and I dont know how to make this better. I want her to be happy again and I dont know if that is even possible anymore in this relationship.

Apologize for grammar, english is not my first language.
<bot>: We have both been unfaithful in the past. She says she forgives me, its bullshit, she doesnt. I want her to be happy again.