Making Yourself Happy:
Play with your pets, the neighbor's kids, etc
Do that extra credit assignment
Do some housework
Volunteer
Keep in mind that some people out there will hate you no matter what, but the people who love you will always be there for you.
Donate nonperishable food to a food bank
Make presents for people
Take a long, hot bath
Go for a walk
Ride horses
Take up a hobby
Go to the mall
Call a friend
Give yourself a make-over
Lock yourself in your room and dance
Read a good book (Xanth novels and Jenny McGrady are good)
Watch your favorite TV show (after your work is finished)
Surf the web
Listen to upbeat music
Tell everyone you love that you love them. Mean it.