there is some pretty good advise in the thread so far. one thing i would add is try to begin a new hobby, preferably something challenging or something u have always wanted to do. if you are into it, it will engulf u. i have played bball my entire life (in my 30's now), year round....town leagues, aau, high school, college. it consumed my life and it has always been my passion. but while i did it, there was a part of me that always wanted to study kung fu.
last summer i began taking classes, it has had a tremendous positive impact for me. it is truly a passion of mine and i wish i had started it 10 years ago.
by starting something new, specifically if it is challenging and something ur interested in, it helps motivate u. it will take you mind off of negativity, as it is a positive adventure.
just my 2 cents.