OK, I would echo QuokkaOfBroadway's plea. Please tell someone, get help.
I suggest you do the following:
1. Make a list of the names of your family and friends. Those are the people you're living for
2. Nail it on the wall of your room. You can also make copies to bring with you
3. Choose something that would remind you who you're living for, i.e.: your favorite color
4. Strategically place items of bearing that color around your home, office, locker, etc
5. Wear a wristband, a lanyard, a ring, etc, with your favorite color of yours
6. Keep all the birthday, get well, and holiday cards you've been given over the years. Your collection will remind you how much you are loved