How can you tell the difference between the voice of god and just your own thoughts?

I've been diligently seeking an answer from god about decisions I need to make in my life. Marriage problems, and just general direction for my life. I pray, I read my bible, talk to my christian friends but it seems that my thoughts are just a jumbled mess. I fell away from God a few years back and made a lot of wrong decisions. I cheated on my wife, she cheated on me three times. We still really care about one another but it seems like our relationship is nothing but confusion now. I want to do what's right but I have no idea what that is. Part of me wants a divorce but part of me thinks I couldn't ever find someone else who understands me the way my wife does. I'm not ually attracted to my wife anymore and when we do have it's not enjoyable for me and almost feels dirty. I'm 25 so is still a very important part of a relationship to me. I want to feel a close intimate connection with her but its just not there anymore and I find myself wondering if I could find that with someone else. I'm just so confused and no matter how hard I search for an answer it never comes. I feel guilty and worthless. I want something more out of life than this.