I know where you are coming from. I had lost 60 lbs, was Very close (within 5lbs) to my goal and then let it all go. Started "coasting" and gained 30lbs back. Talk about Frustrating!! Now I am on my way back toward goal. I have been reading Tom Venuto's The Body Fat Solution
and the first section of the book (about 108 pages) talks about getting over our mental/emotional hurdles. Then it moves on to nutrition & exercise. This book is Really helping me to change my way of thinking. Maybe you can find it in your local Library?
Hope this helps.