Need help and motivation

In January of this year I set a goal of lossing 50 lbs and running a marathon in one year. I have committed to run a marathon in January 18th, 2015. I have almost 40 lbs this year and have 10 more to go. I finished a half marathon this past week and feel I'm on the right path. My body however feels like I've put it through a meat grinder and can use some support and motivation. 3 more months to go, 10 lbs to loose and a 26 mile race to prepare for. I feel like it's mount everest......