Hi Jennifer,
What if your friendship like when you do finally talk or get together? Does she listen to you, is she supportive?

I think if you know you need someone who's going to be there for you and she's not-then maybe you're not as close as you may think or she may not think so?
To me, not calling a friend back for weeks on end is someone who thinks there are so many things more important than me as a friend in her life. Reading your post about this "friend" reminded me of my "friendship" with my sister. Same scenario with the phone call or email, and with the visit to her house-only she would open the door but then shoe would be busy with housework and when she was finally finished- we- no, SHE would talk and it would all be about her, her, and her and and her problems. Sooo, with that said-I may just be projecting. Hmmm?
Anyhow, I agree with White_Iris with your taking care of yourself with cancelling a couple of classes. You're only being realistic and not setting yourself up for failure and I say Bravo to you for seeing that and knowing yourself well enough! Don't knock yourself for that, you should be proud of yourself for that insightfulness.
As for going into the hospital 7 times. You're sick and you need help. When a person breaks a leg do you scorn them for having to go to the hospital 7 times to get the leg fixed, checked up on and physical therapy?
Just because you're not physically bruised and bleeding doesn't mean your pain isn't real.
That's the problem with mental illness. We become our illness. I'm depressed, I'm bi-polar, I'm schizophranic...
Not I have an episode of a depressed mind like you would say I have a broken leg. It messes with our heads all the more so-the last thing we need right?

((((((Jennifer)))))) I hope you feel better soon.