Oh Kas, I promise promise promise that you will feel better. You'll never feel better all the time, but no-one is happy ALL the time.
Have you spent any time on the other forums here (Surviving the big D and Separated, What Now). There you will find people who came here as heartbroken as you who ARE now living full and happy lives. Sure, they have their ups and downs, but very few of these downs and not one of their ups, have a thing to do with their ex's. If anything, when ex's are mentioned, it is to laugh or rant at their expense (case in point, Ginger's reference to "[her] idiot ex" above).
You seem to be reflecting more on your own motivations which is great. Understanding what motivates our behaviour is the first step towards changing it. But, even with all this, I get no sense of who you are. I know Kas the LBS, I know Kas the abandoned child, but who is Kas when she is neither of those. I think you can only work this out not via reflection, but by action. Do things. Lots of different things and tell us about them. Some things will stick and some won't. It is those things that stick that will be the foundations of Kas 2.0.