I really do understand what you're feeling and your thoughts about getting help. It can be hard when people just don't seem to care or understand. What you said was right: You should have a long talk with your mom and make sure she really knows that you need help. And I hope I'm not out of line when I say that it sounds like your mom ought to see a therapist, too. A highly effective technique in treating teens with emotional disorders is family therapy, along with other types of individual therapy (I'm a psychology major, can you tell?

). A lot of people really think that it's just about the individual who is having the problems, when really it is often times the family unit as a whole, among other things. Helping to better the family communication and environment can make a world of difference. I really think that it's important for you to get a good therapist to help you get better. I know that a lot of times counselors will sort of shrug your problems off as "teenage angst" or whatever, not treating it as something that needs to be dealt with, and that's just not fair. Maybe you should talk to your school counselor about what kinds of resources are in your area, outside of school, that can help you. Maybe that will get you the treatment you need. Also, I know that you like to write, I don't know if you do this, but I've heard that keeping a journal of your feelings, or writing letters to people (like your mom) can really help. Also, one thing to do when you are feeling depressed (I know that this can be painfully hard sometimes) is to just get out and do something. Whether it's with friends, or just going for a walk in the sun by yourself (I prefer the latter), It will help.
Keep your head up, remember that you can get better, and stay strong. Good luck!!