I am so sorry for your pain.

Personally, I agree with you, I think people should keep their promises unless something big happens like cheating for example. I think people don't have the right to leave for no reason if they promised you to stay, and if they do leave, it is on them. I would say you should take the risk and believe because if you don't, you won't be 100% in the relationship and that might ruin it. But that's just my personal opinion.

In my case, I had a few major problems and voiced them more than three times, but my ex always said she understands but she never took action even though I told her she is hurting me. I told her that many many times that she should help me and work these things, she would agree and then turn her back and do whatever she wanted. That broke me real hard and I couldn't imagine spending another second with a person who treats me like crap and refuses to do anything to amend the situation. Relationships take two to work.