losing momentum

I was given the go-ahead by the chiropractor and Coach Joe to resume my 1/2 marathon training. I squealed, I jumped around, I was so happy that I could get back on track. Problem? I haven't been able to do it. It's like mentally I can't get my butt on the treadmill or out the door. I don't know how to fix this. Coach Joe wants me alternating 3 miles with Pilates - so 3 miles Monday, Pilates Tuesday, 3 miles Wednesday, etc. to get myself back in the game. This is totally reasonable and doable. Why am I dragging my feet? Why am I acting like, "Meh. Whatever..." when I know what I need to do and want to do. Any suggestions on how to fix this? I know - Just Do It. Any volunteers out there to get all Jillian Michaels on my butt and make me check in with you and harass me until I do? Please? I'm not sure how else I can get it done. (Can't use the husband. He's a big softy. *wink*)