I encourage you to check out my blog "which way to turn" under the blog section on this forum.
Our begining was very similar and I had very similar feelings and fears.
What worked for me was telling Karma exactly how I felt, If I was angry at that point, I told him, if I was grieving what we were, I told him, if I was having trust issues over the lies and betrayal, well he heard about that too.
I found things to distract me. I started knitting, I got a part time job, I blogged and journaled like a mad woman.
Allow yourself to feel whatever you feel, but don't get stuck there.
I made a list of my needs. One of the biggest was I needed to be able to pull back if things got to be to much. They both agreed, at there was a time I had to. I thought I was okay with her sleeping over, but I wasn't. Seeing them together hurt. But one of my needs was to see it. I didn't want anymore secrets or hiding.
Eventualy, as time healed my wounds and Karma and I healed our marriage I became much more okay with things.
Don't rush, but don't stand still either.