Wow, theque, that sounds rough. I had a similar, but not as bad experience. My highschool sweetheart and I were together for 4.5 years. Since I was in college, I was moving around a lot and half the time, I was a state away. So I find out one summer that she met this guy and he was sleeping over for a few weeks before she told me. We broke up. A month later, she was married and pregnant (by choice). That did a lot of damage to my trust issues.
It took me a couple of years until I was ready to start dating again. I was definitely not as innocent as I once was. However, I think I understood people and human nature a little better. And I kept relearning lessons on trust. I have been in an open relationship where the woman I was with lied about who she was sleeping with even though it was ok with me.
It sounds like you and JustMe are doing some heavy growth and changing of values, spirituality and feelings. I hope you can grow in the same direction so you can work it all out.
Do you ever try to talk to Him and work it out with Him? (That almost sounds religious.
) It is hard letting go of feelings that don't quite want to leave. I hope that if you keep re-examining your life and morals, you will be able to align your feelings to your beliefs.