How should I handle my depression?

I’m a 17 year old female suffering from moderate depression. About 2 weeks ago, I realized that something was wrong with the way I was acting, and the way I felt towards things. It was completely spontaneous. But this has happened before to me, and in my previous cases I thought nothing of it. It’s a lot more difficult this time, I can barely live with it.
I have a relationship with another female, so I am bisexual. And recently about 3 months ago my step father committed suicide. Since I am 17 I cannot make appointments myself. I devised a plan in order to tell my mother, which would be, going to the school psychologist speaking with her, telling her my situation, and having her call my mother recommending me to see a psychiatrist. Which worked flawlessly. My mother is now aware of it, and has been trying to make appointments for me, but none of the doctors are calling back. My relationship with my girlfriend is crumbling down because the depression is covering my feelings for her. She’s been talking to my sisters ex-boyfriend, which has been driving me insane, and isn’t helping my problem. I’m sure talking to someone else who appreciates her, is helping her. But I’m not sure whether or not to stay with her. I care about her a lot, and before the depression I couldn’t go a day without seeing her. I miss how I used to be with her, and I can’t tell if I really do not like her. I feel nothing for her. I get aggravated with her, and never want to see her. The first week of this happening, it was as if she died. I was constantly crying at the thought of her, and couldn’t stand looking at her. I figured my step father dying is tied into that somehow. I’m literally crawling in my skin, and I hope that there is some form of medication that can put me back together. I need some reassuring from the Fluther colony. My mother nor family knows I am bisexual, but my family is aware of my depression. Thank you in advance for your help.