I'm 13, and everything in my life is so effed up?

I'm 13 years old, which is the first thing I should mention. There are so many problems in my life right now, and it's really getting to me. First, my dad. He's 58 years old, a smoker since the age of 15 but trying to quit, and a good candidate for Alzheimer's disease. He has a lot of trouble remembering things, and it runs in my family. He is also a very good candidate for lung cancer. His father died from a stroke or a heart attack before I was born (I forget...), and his mother just died from lung cancer. She only smoked for 20 years and quit about 40 years ago. He is also an alcoholic (not a severe one though). He got really, really drunk a couple nights ago and stumbled and hit his head on the balcony. He had to get stitches on his forehead and his eyes are bruised, and his nose is cut up. Next, my mom (50 years old). She is severely depressed. Her mom committed suicide before I was born, and her dad is suffering from congestive heart failure. She does A LOT of weed every night. She is also very, very dramatic (being depressed and all) and cries about twice a week. She and my dad don't get along at all and my dad gets frustrated really easily. Her mom killed herself when she (my grandma) and her husband (my grandpa, the only grandparent still alive) got a divorce. If my mom and dad ever get divorced, which they probably will since they don't get along at all, I really think she will do the same. All my mom ever does is loads up on anti-depressants then goes to sleep. Oh, and smokes weed. Then, she loads all her problems with her father and my dad onto us and cries to us. She is overweight too, and she never ever eats. It's scary. But she never loses weight. Then, there's my sister. My mom doesn't get along with her either. They have had two fights today alone. My sister is 17 years old and goes out and parties a lot. She is a really good kid though, like she has never ever done weed (thank god, since it runs in my family haha), has a 4.7 GPA, and is still a virgin (awkward?). She just likes to have fun with her friends on summer nights. She does drink, but not excessively. But the thing with her is that I think she has some form of mental disease. I think she might be anorexic. You can see my question that describes her symptoms here http://answers.yahoo.com/question/index;_ylt=AqD_JYYoNhQf9Z1t2QrCZaPty6IX;_ylv=3?qid=20110702014834AAzbU0d she might also be bipolar or something. She just gets so angry all the time. You can read the story in that question about her throwing her phone at my mom. Then I have a 20 year old brother, who's actually fairly normal. He smokes weed, but what 20 year old doesn't? Then there's me. My brother lives far away (he's in college), my sister is always out with friends, and what 13 year old wants to chill all day with her parents? I mean, sure, I go out to dinner with them, I do my mom's makeup, I go downtown with my dad, but I'm not about to spend all my time with them. Especially since they're so... depressing to be around. Here's my problem though: I don't have many friends. Girls in 7th/8th grade are just plain awful. I have about 3 friends that I would actually call up and hang out with, and I don't even like hanging out with them. My sister even told me that the nicest friend I have is a *****, so it's not just me. I can't make any new friends, it's summer! Hopefully, I will in 8th grade. But anyway, I have nothing to do. Ever. So all I ever do is eat, run on the treadmill (I don't do any sports, so I feel the need to), and watch TV. I use TV like a drug to get away from my problems. When I watch my favourite TV shows (Friends & Ugly Betty) I feel like I'm in a different land, away from a reality. I spend almost all day everyday watching TV or on Tumblr. I go to sleep at like 7 AM and wake up at like 2 PM. I can slowly feel myself becoming depressed. My dad says I live the life of a pothead, minus the weed. Everything is so fu*ked up. I just wish I was young again when I was oblivious to all these problems going on in my life. There's nothing right about my life. Why does everyone in my family have such problems? They need to learn how to act. Their 13 year old daughter is slowly slipping into depression, because they're all dumping their problems on me. I feel like the song Family Portrait by Pink describes my life fairly well. "Mama please stop cryin', I can't stand the sound, Your pain is painful, And it's tearin' me down" "It ain't easy, growin' up in World War III, Never knowin' what love could be, You'll see, I don't want love to destroy me, Like it has done my family" "In our family portrait, We look pretty happy, We look pretty normal, Let's go back to that, In our family portrait, We look pretty happy, Let's play pretend, Act like it goes naturally". It's weird because when I was