:::OshnSoul:::

Hey, we all make unwise choices from time to time. And the only way to get over this is to remember that. We live to experience who we are by doing things that define who we aren't. What we call "mistakes". There is a reason they are called mistakes- "mis"-"takes". Just like in a movie, you get another shot, no big deal.
Even if it seems like a big deal, there's always tomorrow and there's always another chance.
If she forgave you, you should be able to forgive yourself.
Don't be so hard on yourself.
And being open and honest was the wise decision on your part, even if it was hard and it hurt. If you aren't 100% completely open & honest with your SO, you are carrying a weight bigger than you can handle and it will just keep growing and effect your relationship, possibly causing it to deteriorate. Keep that in mind. I have been in your position myself, but once I let go of it all and told the truth, it was painful, but I was forgiven and I felt a whole lot better than I did holding it in.