How can I get help with issues around sex and shame, stemming from childhood?

As a child, I was humiliated frequently by my mother and sisters if I showed any interest in women, or anything of a sexual nature. I will not go into the details, but it has led me to become increasingly embarrassed about sex, nervous and withdrawn when it is suggested. I am in a loving marriage and really want to change my patterns of thinking, from the deep shame I feel about it, whenever it happens, or I think about it. My wife really deserves so much better and I feel that I cannot keep running away from my issues.

Prior to marriage - I found that I would often get to the point of intimacy with women and then run when push came to shove. There is no problems with feeling attracted and wanting sex - there is just an overwhelming voice in my head when it is about to happen - I make my excuses and remove myself from the situation.

Since I gave up alcohol, a few years ago, the issue is far worse; I think that a few drinks broke the barriers down. Unfortunately, I cannot go back to drinking, due to medication I need to take.

What kind of therapy should I look for? It is not something I feel I can talk to friends about.