I dont want to live anymore.....?

To be honest I don't see the point of me living. I'm just taking up space that could be used for somebody else. My cousin died about 2 years ago from a shooting and died in the hospital. I can't go a day without thinking about him its killing me inside. Than later on my uncle I loved him too death. I cried my *** off and still think about him everyday too. I've also got caught have weed multiple times and my mom thinks all I do is smoke weed. She calls me a failure and that I don't want nothing in life. I've moved on from smoking weed long ago but she still puts this weight on my shoulders. I also found out I failed the 10th grade. It's killing me inside right now. I feel so depressed and don't even want to be here anymore. Than in august I have to back to school in 10th grade again and get so much **** from kids. I swear I'm just a failure and a dumbass I can never be successful with anything no matter how hard I try. O just get bashed about having underachieved grades from my parents I busted my *** this year and o failed because I missed 1 ******* credit. My sister constantly says what are you gonna tell everyone your in 10 grade again? Than just walks away and laughs. That **** really is getting to me and making me feel worthless and depressed. I don't even have any sort of appetite to eat . I just don't feel like being here anymore. I've also get made infront of how o look. Some people say I'm cute. MOST people say I look like a alien of a turtle. This is just too much for me . I can't cope with it. This is truly killing me inside slowly.