So here's the thing....

I'm 17, a junior in high school, a (fairly closeted) lesbian, and my depression is getting worse. 
I'm just stuck in a hard spot where I know I need to do something like go to therapy/get on an antidepressant or anything else to just get me through this, but my parents blame my symptoms on being bitchy and if I mention therapy they'll blame everything on me being gay. Even if I could go see someone my parents are so against medications like that they've made me cut friends off who were on them.I'm terrified of everything my parents could do to make it worse, they could tear my girlfriend away and she's the only person holding me steady now and I can't take that. 
I just feel like I'm drowning, I barley eat any more, my grades are slipping, and all of my relationships are being affected by it. I just want help but it's so far away right now and I don't know what to do. I hate feeling myself being destroyed like this and I don't know where to turn.