Lexicon,

My therapist tells me that emotional abuse is the worse form of abuse. That's probaly why you're taking comfort in someone else...searching for something to ease your pain. You are a GOOD PERSON. Honestly, I don't feel that you've done anything wrong. Maybe couple's therapy could help you out. If it's intimacy issues your bf will never know if you don't share that with him.
I do belive it's a good idea to break it off with the new guy just until your sure you don't love your boyfriend. Or you're sure the problem your having isn't worth working through. Sometimes we feel we don't love somebody as much as we did to only find out we still do, and most of the time we find out the hard way.

I hope things get better for you and your bf, and no matter what happens you are a good person.