Advice
Irish_John, I'll give you the advice I give to everyone: Pray. In your case, pray for God to reveal His will to you. If it is His will that you remain single for the rest of your life, so be it. If it is His will for you to settle down with someone, so be it. If it's His will for you and your ex-girlfriend to reunite, so be it.
The point is, don't close yourself off to possibilities, and definitely DO NOT write off godly, romantic relationships with women just because your ex-girlfriend broke your heart. Take me, for example. I've had my heart broken so many times, it's ridiculous. But I'm still willing to keep myself open to the possibility of settling down with a wonderful Christian man, one who has been chosen by both myself and God. (I'm interested in someone right now. I'm just relying on God to put the puzzle pieces into place, if this fellow is the one who's for me. If not, I'll be sad, but I'll keep looking. And I'll still have him as my friend.)
The point is: Don't allow a past relationship to affect your future.