the2ofme,
It's good to see that you are posting and sharing with us.

Just for the record, at my age, anyone under 45 is young.

Jmo again, but her not openly admitting to it may be because it was only a part of growing up. Many people will experiment when they are young, and it ends there. There is no shame/guilt associated with it. However there may be some embarrassment...we tend to look back and sometimes feel foolish.
My comment to you about letting her live in peace is a valid suggestion. Why should she admit to something like you being her test subject?? Changing your mind about her being angelic? Talking to her about something that happened long ago...what purpose does it serve?

the2ofme, there is a vast difference in seeing a shrink for medication and therapy for your problems. It may be a start in the right direction to find a therapist to guide you through these things.
I "hear" some respect for your wife in this new post. She's done everything she can to make you happy, share a good life, raise children and she is still by your side.

Your last paragraph about possibly wanting out of your marriage without hurting your wife and kids...any way you do it is going to hurt them. There is no easy way to end any marriage, but it's especially hard to end a long term relationship that has brought two children into this world.

If this is what you want then be honest about it--as honest with yourself as you can. Counseling, either individual or couples, will help you sort out things and clear your mind. It's worth the effort if for no other reason than you tried everything before making a decision.

I applaud your honesty in admitting your memories are more of her than of your wife. It only adds to the likelihood that something needs addressed, in fairness and dignity, in your life. An objective person via counseling will help you focus on all of this...in the long run, it is still your decision, though.
I would sincerely like to see you work out a solution to your problems...

Everyone involved deserves to be happy...

Cap