You're depressed. You associate failure with The finals so you party, because partying makes you happy and feel better about yourself. Does your college know about your depression? Perhaps, they'll let you make up for your tests? See the school therapist or talk to a close friend. Depression is normal. It can be chronic or a one time thing. It happens and eventually it will pass. In the time being, start writing or take up art. Both can be good ways to channel your feelings.
Good luck:)