I get the feeling! I go in and out with struggling to get myself to go, and it's all a head game for me. I read something once that helped to make the head battle a little easier... just make your daily goal to just put on your gym clothes and get to the gym.. don't think about being miserable once your'e there or how much time you have to put in. Get over the hump of just getting dressed and going - that is totally doable! Then, once you're there, chances are you're going to do the rest.
Sounds stupidly simple, but it worked for me!! Good luck!!