Am I depressed? As explained below, I dont know anymore.?

Basically I hate life. But I do get on with it. I don't know how people can be happy without being rich, pretty and sucessful. What is life? Work, work, work, death. But as I said... I get on with it. I have to... there's too many people who would ask questions if i did what i wanted and left college. I actually enjoy college... I only want to leave because I would enjoy sleeping all day more. Is this the wrong attitude? I really dont know anymore. Sometimes I think I make myself feel depressed to get sympathy... I don't know why - I never even tell anyone. I've started self harming again, but I dont NEED to, and I'm not addicted. I just want to. I don know why. I don't show anyone. I want to emigrate. I can't differentiate between sanity, depression, SAD (though my symptoms have got worse lately, but it could be coincidence). Please help? I hate my body but I over-eat. I am glad to be alive sometimes, but others, to be honest, I wish I was dead. Please don't say go to the doctors - I'm not going to. I think I am developing a multiple personality disorder. The depressed me and the happy me. I go from one extreme to the other. Not in a bipolar sense though. So yeah... any thoughts?