lost it

first off, im sixteen years old and i’ve never felt so worthless in my life.
Lets start from the begining.
When i was young my dad abused my mom so eventully my mom left him and then one night he did something bad and then had to go to prison for 4 years so i was dadless until I was in seventh grade. During the time I was gone my mom had a boyfriend that lived 4 hours away so I was always alone. When my dad finally got out my mom and him got back together and then my mom realized it just wasnt working. My mom eventually met someone new and my dad couldnt handle it and on November 7, 2007 I found out my dad had hung himself in his apartment.
Only a few weeks later I had to move in with my mom and her boyfriend in a different town. I hated it. I was miserable. Eventually we moved out and went back to our town. I was completely fine with my life kinda, i had the greatest boyfriend ever he is seriously completely amazing and helped me through everything. I eventually learned to cope with everything. We had been dating for a year and six months and not even a month ago he dumped me out of no where. I took it really hard, especially when we taked a few days later and i thought we were getting back together. Eventually a week laterI found out him and this girl were starting to like each other. (we’re sophomores) well she is a senior. Well now they both do like each other and he barely talks to me at all. A week ago I found out my grandpa has cancer. My mom also wants to like with her boyfriend but have me live here with my brothers. So i’ll pretty much be momless. My bestfriends are always with their boyfriends, and I cannot move on from my ex boyfriend. I’m still completely in love with him and his family still means the world to me. I cut myself constantly, and Im always alone cause my mom is always at her boyfriends and I live just with her since my brothers live together. My grandma ( dad’s mom) doesnt talk to me cause she blames me for one of the reasons he commited suicide. I suck at school, I’ve got bad grades now:/ I just don’t think I want to be here anymore.