ahhh.. yes. The old "I have to be someone different when the wife is watching".
I've been there too, in the past.. and you're right, it's not good.
Let me guess.. if you were truly yourself, you'd be more attentive to the "third", maybe more romantic, more caring, but you can't because it would start jealous feelings from your wife?
Unfortunately, I think what might be off-putting about threesomes for you is that you dislike being dishonest.. by hiding your true self and acting differently, you feel as though you're lying?
That's what it ended up being for me, back when.
Although I understand the love for a person that makes you willing to give up these things and make the changes you're making..... consider this.. what is she compromising on? It's a two way street. If you are giving up so much, changing your life in such an extreme way, I would have to hope that she too is making radical, lifechanging shifts.
Either that, or this arrangement isn't all that healthy, really. One person should not do all the compromising..
It's a partnership, right? Team? Don't just give in to give in, and end up resenting it later, that's just not going to help, I'm afraid.