Getting A Divorce And Starting Over

I have been married for 30 years, I thought she was my soulmate, but apparently I was wrong. We were going through some financial problems and she started talking to a "friend" of ours and getting advice. This was 2 years ago and now she says she not "in love" with me any more and wants a divorce. She has admitted her affair to me with him and wants too be with him now. I am fine with getting a divorce because I may forgive but I will never forget. My main problem is.......she's the only woman I have ever been with sexually. I am 51 years old and scared to death of starting to date and being intimate with a woman. What do I do to overcome this fear???