Hey Travis, If you feel that strongly about your ex, why is he an 'ex' rather than your 'lover'? It seems you're afraid of being with someone and afraid of not being with them at the same time. What a dilemma hey :-).
Mate, I'm not a professional or anything but I agree with Laura. You may never be happy in either situation until you can be happy to stand alone. When you are happy just being with you, you will be more comfortable being with someone else and your reasons for being with that person will also be deeper. Otherwise when you're alone you will be wishing you're with someone and when you are with someone you will wish you're alone. I don't know if all that makes sense from an emotionally challenged Aussie, but hope it helps. Pete