Hi Hilary.... Sometimes I just don't think about it, put on my trainers and do a run before I go to bed ...knowing that although it'll be hard, I'll sleep like a baby! It's overcoming it mentally for me because once I'm out there, Im ok. I've managed to stick to my training plan more or less I've only missed a couple of short runs but I've fit in all my long runs and I'm up to 18 miles,. Got a 15 to do today then 20 next week before taper.
Good luck in training
Bex.