I’m dating a girl and I’m unsure what to do

I’m 18 and my gf is 17 (turning 18 next month) and I’ve had a situation that I don’t know what to do about. I’ve been with her for a little over a month and been talking to her for about 4 months, This girl is genuinely one of the prettiest girls I’ve seen and I knew from the start that I wanted her. She has had an ex in which she’s had a history with which I won’t go into but they did date for 2 years before I met her, there had been multiple occasions in the time I’ve known her where she has called me his name, which hurt me and I spoke to her about but the main thing which I discovered recently was that she was secretly still in contact with him and not in a harmless way and she was saying some humiliating things to him about me but nothing crazy. I confronted her about this the other day and we worked through it together. We don’t argue at all and the she suffers from a lot of mental issues. I genuinely want to stay with her but don’t know what to do about this situation because I don’t think I could ever forget it. She said to me that she has regretted it deeply apologised hundreds of times and she also said that she doesn’t want it brang up anymore because she doesn’t feel that it could be resolved if we talk about it a lot but it’s causing me lots of stress and constantly fearing that when she isn’t replying to me or being dry at that moment that she is replicating what she has done.

I guess I’m asking if these feelings will continue forever or I will I never get over them and also what i should do with the relationship?