Is it safe to assume you still love your husband and are committed to the relationship? I hope this is the case, because if he is being honest with you, you can get through this together.
First, let me say, everything you feel right now is legitimate and appropriate. The truth is, you have a world of pain to go through before you get to the other side. There is no avoiding that and I think you know it. Also, damage control is important to you and that is very understandable. Shame and humiliation only compound the problem.
So, if you love him and are committed to him no matter what, tell him that. Tell him everything you feel and express your hurt to him. Don't hold back, but saying things just to hurt him will only makes matters worse in the long run, I suspect. Then tell him that you need something extremely important from him: brutal honesty. If he knows you will stand by him up front, he is likely to do this for you.
Trust has been broken and will take a long time to be restored. The first step is his complete honesty, not only with you, but with himself. As much as you want to think of him as a freak, he is not. Obviously, he has issues with his sexuality, but he may not necessarily be gay. Sexuality is complicated and expressed in many different ways.
There is no point obsessing about gossips...that may or may not happen. Also, set aside the worry about telling aging parents and children. Don't borrow from tomorrow's problems, you have enough with today's.
I don't think many of us can even imagine what you are going through. You need understanding and guidance. He needs these things, too. He's not the enemy, he's your husband.
I think this seems particularly ugly because it is about sex.
If he were out at night getting drunk or developing a gambling problem, it would be hurtful, but less shameful, I imagine. Try, if possible, to see him as someone who desperately needs help...mostly from you. You have had a lot dumped on you and you are only just beginning to deal with it. Your need for help and understanding are as great or greater than his.
The two of you need to do lots of communicating and seeking wise counsel. It's good you feel you can come here. We may not be much help, but we can offer an understanding shoulder to lean on and guys who will listen to you.
Don't panic, if you can help it.
