I just don’t know how to make everything go away……..

Ok, this is my first time writing on this so I’m sorry if it’s not right. I just don’t know how to make everything go away is the only title I could think of.
Alri I’m going to give you a little back story. I have always struggled with myself I have always hated my body,my face my personality my everything. I have a lovely family and have always been given everything I have asked for and still not being happy sends me into a deeper depression and state of hopelessness when I’m surrounded by lovely thing but I am still the problem. I have had suicidal thoughts since the age of about 13/14…as long as I can remember but only thoughts never actions only now in the last few mouths I have been self harming but in the way of scraping myself until I bleed pulling my hair out and just digging my nails in. Iam 19years old now and feel in a state of isolation iam not smart and will never succeed at anything I will be stuck in the same no skills needed job all my life and die alone. This is jut the general fear that I’ve always had and I use to be able to snap myself out of it but now things have taken a turn for the worst. My situation has gotten so much worse the one thing in my life I felt like I could not live without, made me happy and has made me see life is worth living is my boyfreind. He found out his dad has cancer and not long to live he is devastated and broke up with me to concentrate on his dad which I understand and commended him for wanting his dad to be priority. But because he was so unsure about the breakup it gave me a glimpse of hope so I begged until he said ok & took me back.since what I thought would make me happy again has almost made things worse. The thought of me being a strain on my boyfreind and forcing him to be with me is making me feel like ending my life and letting him and all my family free of me because iam such a burden on them all.also the feeling of guilt makes me sick thinking my boyfreinds dad is dying without a choice and for so long I have wanted to end mine if I could I would swap places in a heartbeat.only half of what I would like to say is here because there are so many feeling & thoughts in my head right now I cant even make sense of them all. My heart feel like a dagger with every heart beat I just want to go asleep and never wake up. That’s the only way I can see everything just going away.
Thank you in advance for anyone who read this or replies. Sorry about the mixture of stuff just needed to get it off my chest.