I think it's important that you figure out what you really want before you take any big steps. Therapy will help with that.

You are NOT a loser. Everyone does things they reget (I'm divorced after only a year of marriage so I should know). But most are able to move on.

You make her out to be some perfect woman, but nobody's perfect. It's easy to forget that when you're in love. Especially if you love from a distance. I know you don't want to hear this, but it's risky to let your entire happiness depend on a woman that's already in a relationship.

I wish I could help you more, but you are the only one who can figure this out... Let me know how therapy went?

The only thing I want to ask you is to try to remember that the choises you make, affect your kids too. You sound like a good father so I think you will.