<human>: Can you provide a brief overview of the text?

I [23M] fucked up, in a big way, by betraying my girlfriend's [21F] trust. It's been a few months since I came clean, and I'm asking reddit to take my word for it that I've been doing everything I can to make up for it.

Day to day, we're fine, sometimes great, just like your average imaginary couple. But every once in a while, something will remind her about my betrayal, and it's like we go straight back to that hell, starting from square one and clawing our way to get back to "normal". We both hate this pattern, but she feels helpless from feeling this way whenever she's reminded of it, and I feel helpless when it happens of being able to... do anything. "Just make sure nothing ever reminds her of it", feels like too much like an unhealthy, short-term solution. 

Reddit, do you know of any relationships (friends of friends, your own relationship, historical, famous, whatever) that have survived a massive betrayal to have a long-term strong and healthy relationship? If so, what did they do? How did they do it?
<bot>: We hate falling back into this abyss that my betrayal caused. How do we/I strengthen our relationship so that we don't forget this, but grow beyond it instead?