You're thinking her sexual attraction is based on your appearance and bedroom performance. However, many sexual problems originate outside the bedroom. I remember when my first marriage ended, I'd rather have stuck pins in my eyes than have sex with my husband. It wasn't because he was bad looking or bad in bed....it was because I became repelled by his attitude to life.
What's your relationship like? You say that you feel she doesn't respect you and treats you like a boy. If you are reading these things correctly, I'm going to suggest that her not wanting sex is due to relationship issues.
Tell us how she views your marriage. Is she happy and in love with you? Do you have unresolved issues? Personality issues?
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.