I think that a lot of us are as confused by her behaviour as you are. Hence the assumptions being made.
I have a dear friend who could easily orgasm 10-15 times. What posters here call exhausting she calls wonderful - and this is why I won't say that your wife is faking. But my friend also has a really high sex drive and discusses sex openly and easily - which makes complete sense. I don't think any of us understand why your wife would enjoy sex soooo much and then not seek it out.
I think your only way forward is with open and honest, two way conversation. But if anything is to change, she must WANT the change.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.