1) Surround yourself with positive, like-minded people (joining an online support group like WOWY is a wonderful place to start! http://beachbodycoach.com/esuite/home/katygillis/join
2) Those people who are negative? don't listen to them.
3) Write a "business plan" of why you want what you want, how you're going to get it, and the rewards when you get there. Follow it :) and change it when needed.
4) Pay it forward. When you have achieved your fitness/weight loss/coaching goals, decide to help other people do the very same thing you did.