Hi J-bird,
You're wise to look for some advice on this topic, and I respect your efforts as such.
Let me give you some wisdom, from my own experience... my wife and I got married when she was 20 and I was 22... we met when she was 15 and I was 17, believe it or not.
So in many ways, we grew up together, shared a lot of good times, and I had expected that she was happy. But she apparently had a lot of those pent up "spread my wings" feelings that she never shared with me. Well, she ended up having an affair with a fellow student years ago, hid it from me, and in doing so, built a wall around herself... which made her second (current) affair much more possible.
Her current affair has literally devastated her. She's losing everything - her security, her family (me), the respect of her parents, etc. - all for a guy who's proven himself to be a cheater. Her desire for independence and freedom was something she talked about a lot after the affair came into the open... and when we finally separated (I left), she suddenly was "given her wish" - freedom. You'd think she'd be happy about it... but she isn't. She's an emotional mess, depressed, has developed skin conditions due to stress, cries easily, has spent thousands on counseling (with no apparent results), etc.
No... that freedom she so desired sounds great in theory... but when forced into reality... it sure seems a lot different... especially knowing you're losing everything for something that's only a concept... the reality of the situation is that "freedom" only means she gets to suffer her pain alone - with no-one but an OM who's naive and selfish to confide in (and a girlfriend who's divorced and been through countless failed relationships).
And here I am... standing up for myself finally. She knows I'm "best" for her (has even admitted such), but has dug herself into such a deep, deep hole that she can't find a way out. I recount my story as a warning of what dangers lie ahead if you're not careful. I think your feelings are normal and can be dealt with - if you look for constructive outlets. Use it as a reason to grow and learn, and you'll be able to look back and smile, not with regret and pain.
"Smart ones learn from their own mistakes. Truly wise ones learn from OTHER people's mistakes!"