Bleh, closeted guy here, looking for advice

So to give some context, I live in a somewhat upper class community, where I live with my pretty conservative parents and two siblings. Friends family, almost everyone I know thinks i'm somewhat weird i think, and they think I'm straight, so I think that if I came out I would weird out everyone close to me, and be a disappointment to my parents, who already view me with secret disdain because I'm depressed and failing high school. I don't know whether my depression is caused by my secrecy, or maybe its just me, but like, I'm in this rut, because the more the depression weighs me down, the more I can't really be open about myself, the more I hate myself for being myself and its all just a mess of feelings. I haven't ever told anyone about myself, though a couple of friends know about my depression. But I also had this girl say she likes me, so all my friends and family are convinced I'm straight. And now I'm worried that if I don't graduate High-school then Ill never be able to go to an away collage, and never be able to do something like date freely and whatnot. I'm not unhappy with my family though, everything is great compared to other people's situation. I just don't want to ruin my relationships, and make my parents see me as a disappointment.