Invite your husband to read some of these threads. I did that and believe me it's worked miracles on my previously VERY VERY closed minded husband of 10years.
His log in is Maca. Check out his posts.
First and foremost-you need to be thoroughly honest with yourself and then with your husband and lastly with your friend. It is always the other persons right to choose to walk away if they can't deal with who you are, but they deserve the right to decide based on the truth of who you are, not on a piece of info.
Read lots-You might click my name, go to my profile and read through my posts. There is a LOT in there about the topic you are dealing with as I was/am in a similar situation. It was hard as hell to "drop the bomb" so to speak. We have four kids and all are still at home. Him leaving would destroy them as well as me. But I had to be honest if our marriage was going to be real. I didn't want a marriage based on a lie. I took my chances.
"Love As Thou Wilt"