I've recently adopted the philosophy that everyone has an important purpose in life, like how you believe in an angelic purpose -- if you feel that way, strive to fulfil your life goals. =] if you're having a hard time deciding on those goals, it's always a good idea to kind of take a step away from the negative feelings, and analyze the thoughts you have. Maybe consider a few hobbies and see if you'd be interested in a future with those. If not, explore any other options that you feel strongly about looking into. If that makes sense.
Why do you feel angry when you think about an angelic purpose? Part of life is pushing past those barriers and obstacles, so try to look at that in a positive way. You'll feel stronger.
As for hating the human form...I'm not sure what to suggest there. Just try to use it to the best of your ability. I'm sorry I'm not very helpful with this. D:
& lastly, depression...hmm, you'll need to elaborate on that. I might be able to help there.