In the group, we try not to give advice. But here, Mac responds to an email from a group member who asks for advice, saying that he and his wife are in couples therapy, and the therapist has suggested writing down all his sexual experiences with men.
Before or during your marriage, have you and your wife discussed every hetero encounter you have ever had? Have you discussed every encounter she's ever had? If not, are you and she going to start now? If so, why?
There are some people who feel they want to be and can be completely open to their partners, including blow-by-blow accounts of every kiss, handjob, or fuck. There are others who are willing and able to trust their partners despite not having such a detailed understanding of their partner's past.
If your wife is type 1 above, and you're type 2, you'll have to work it out between you and I would expect that process to be long and hard, especially given the circumstances. If, on the other hand, you're both the same type, I would hope that you can come to an easy resolution of this particular issue.
Your email indicates that you're very reluctant to do this, especially in detail, which is completely understandable. I urge you to think about why you're reluctant. Is it because you don't want to share that part of your life with your wife because of the current circumstances, or is it because you're still having a hard time accepting it yourself? If it's the former, you may have very good reasons to avoid doing this; I imagine such a piece of paper becoming part of a divorce trial and shudder. But if it's the latter, think about whether you're still fighting your way to self-knowledge and self-acceptance. If you are, maybe you're resisting this because it will force you in some ways to confront who you have been, and maybe such a confrontation is what you need to take the next step. In that case, consider writing up your past in great detail, for your eyes only, and look it over. What parts are undeniably you, perhaps in spite of the fact that you've been denying them for however many years? What parts are bad choices you've made, that you'd like to avoid making again? What parts are good, self-affirming choices and experiences that you want to have part of your life, and would want to share with others because they made you happy and proud?
The single most important thing you can do is to understand and accept yourself, the way you really are. Once you've done that, you will know what else you must do, what else you want to do, and you'll be well on your way to making a life you can be happy and proud of. The other steps will still be hard, but you'll have the "I can do that!" feeling instead of the surrounded-by-insurmountable-obstacles feeling.
You'll know you've gotten to that point of self-acceptance when the idea of writing down your past experience and putting it on display doesn't trouble you at all. I'm not there yet completely myself, and I doubt very many people are, but it's a good goal!