jess thank you for being comfortable enough to post how you are feeling. it seems like chronic depression, but i'm not a pdoc. your emotions tho are similar to mine when i was incredibly depressed. doom and gloom, helpless and hopeless. i don't quite understand why you can't see your pdoc alone. you need to feel that you can be totally honest and express your mood. i don't know your age but next visit to pdoc i'd request this and see what he says. the only way he can really help you is if you tell all. maybe printing out your post to give to him is a start if you're uncomfortable telling him in conversation. or mail it to him. ask for private sessions with him excluding your parents.
don't give up. you deserve the help you need.