What mental illness could I have?

I honestly don't think you have a mental illness, but you need to change your personality ASAP. Just be yourself and don't lie. People love you for being you and hate liars. Making friends is not hard, the test is keeping them. You may have depression now, but you would be in a different place now if you just didn't lie to people. Just look into yourself and learn to love yourself, if you can't do that, well, you won't make any friends. People try to do alot of things to impress people, but the thing that people love is your true self.