

I don’t know that you can fix it because it sounds like her issue. I obviously don’t know the contents of the video but it sounds like you have done everything to assure her that you are committed to her and want to be in a relationship with her. People have pasts and if she cannot accept that then it is something she needs to work on not you.
Well, I can see how that would be upsetting. Definitely holding on to intimate videos of an ex is not a good idea. Still, if it was an honest mistake then it is still up to her to decide if she can move on. You have done all you can.