Feeling Guilty over nothing.

My boyfriend and I have been together for over two years. Before we started dating, I had been in another long term relationship in which I had sex for the first time, it only happened once and then we unfortunately broke up for other reasons. I feel absolutely SO guilty that my current boyfriend was not my first because I was his. I know I shouldn’t feel like way because it’s okay, but has anyone else gone through this? How did you make yourself realize that it “doesn’t matter” now? Thanks!