While I COMPLETELY and totally relate to vacillating between feeling the elation and just general awesomeness of feeling like you can do anything and the feelings of frustration and maybe even guilt when you start to think you should be doing more I agree that you should get off your own case a little.
It's OKAY to not have identified your dreams yet...let alone realized them. You are 26! you have only lived a quarter of your life (fingers crossed). Would you reasonably expect a freshman in college to definitively declare a major? If you manage to figure it all out soon WONDERFUL! you should consider yourself very lucky but if "living your dreams doesn't actually start in the next year or next ten or 15 years that's okay too.
Now as for self evaluation and empowering yourself to make decisions that will make your life better or make you happier: those are things that should happen on an ongoing basis and I really admire you for doing that.
Why is it necessary to wait until you have a "healthy body" (if your body is in fact wholly unhealthy now) to make changing decisions? In fact wouldn't a "unhealthy" body need or benefit from those changes more than a healthy one?
Lots of signatures on the board have the saying "eat/work out for the body you WANT, not for the body you HAVE" I think a great corollary for that would be to "Live like you have the body you want, not the one you have."
It's one thing when you have a genuine physical limitation ( and I don't know if this is your case, I apologize if it is) but I think much of the time we hold ourselves back from doing things that have very little to do with our weight ( I actually wrote a post dealing with this recently, you can check my profile for it). My weight does directly prevent me from going sky diving (which I REALLY want to try). Companies wont let an obese person go up. But my weight does not actually directly prevent me from walking into a bar, my feelings and insecurities about my weight and appearance do.
Sorry for the long post. I hope it wasn't preachy.
Good luck on the introspection and happy pre-birthday!
Patsy