I just get the feeling that killing myself will set myself free

"i dont have the slightest clue of what's going on with me... i have bad jealousy issues, my mood changes from time to time and i wanna be alone, i think of commiting suicide when i usually get sad, and sometimes im just plain ol depressed. as a child i use to be so happy before my dad's girlfriend came into the picture and took a dump on my world and put reality right in my face. i still was a kid when that happened and from then on there my childhood was rough, and as i grew up more problems started to come to surface. i started gaining weight, my step mom got locked up, my dad was a working fiend, my brother gave me hell, i had alot of lonely nights, i was teased in school, and my mom wasnt around to show me any love. this happened when i was between the ages of 8-13. and when i turned 14 i moved with my mom and my dad kinda walked out on me. my mom teased me about my weight and called me alotta not so good but not so bad names.i wasnt teased in school anymore, thank god, but things still weren't easy. im 18 now but three years ago was when my dad officially walked out on me and i miss him so much and his absense saddens me so. i constantly stress and worry, and most times i feel happy but the smallest things makes me sad or i start to feel like shit, and then my self esteem gets lower than it already is. now i stress more than ever bcuz my mom has cancer and shes getting sicker by the moment and im left stuck in a house that makes me wanna kill myself all day taking care of her and my lil sis.( i just had to shorten the story, its deeper than that). at a young age i tried to kill myself and tho i dont ever try to do that stuff again, i just get the feeling that killing myself will set myself free....idk i need help my mind is clouded and i have such great friends but my negativity may drive them away. i try not to act like a "bitch" but i cant help it, sometimes i like to be the rain on people's parade. I get jealous when i see my friends having such a good time with each other and not with me(even tho they are trying to have fun with me im just not realizing it), then i just stop talking to them, then start ignoring them, and then i just want to walk the other way and be alone...the littlest thing will flip the mood switch me, i dont understand...."

Source: http://community.mentalhelp.net/showthread.php?t=2635