I dont know how to get over my depression. help?

I'm 17. For years I have been faking happiness because i didnt want to push away what little friends I had. I fight with my parents and my sister, and pretty much the rest of my family. I close myself off from everyone by staying in my room and often times i just lay there and cry. I dont see the point in finishing high school even though im in my senior year, because my dad has made it VERY clear to me that going to a good college isnt possible because of the financial aspect of it.

One of my favorite things to do is watch tv or read books. (I used to HATE tv) I am constantly watching or reading because of the simple fact that the worlds in the shows/books are way better than my own. I wish I didnt live in the world I do. Im overweight and even though i go through great lengths to lose weight it just stays on. all i want is to be beautiful.

even though ive tried so hard to keep around friends instead of pushing them away, slowly but surely i have lost my best friend.
this summer she replaced me with a new girl and i constantly think about what i did wrong or didnt do.

i have no one. my mom is emotionally neglectful and i mostly feel like im invisible in my house.
i am constantly stressing out about school and life.
i have no future.
i have no one to look out for my best interest or any true friends left at all.
I dont know what im still here for.

what do I do now?