I want to die! Please help!

Hey. So my story starts on the 15th June 2017. I got with a great guy and i thought he was going to be the one for me. I am only 16 but i thought it would last what makes this worse is that i am a care kid with lots of problems. His name is Jack i asked him out before i got on the bus to go home and he said yes. He took care of me texted me everyday making sure i was alright, forced/made me eat ( i refuse to eat as i think i am fat) and he made sure i took my medication. Last Thursday i told him i was moving back with my dad but had known a few weeks. He had a go at me and told me i should have told him sooner but it didn't change anything as he moved to Blackburn and i would be moving a tiny bit closer to him. Everything was going great till he started going all distant with me and wouldn't answer my text messages or calls. He dumped me on Sunday leaving me crying every day since. He told me that he didn't want to be in a long distance relationship were he only gets to see me once a week. I told him i understood and it was fine as we were stills mates at the end of the day. But then Monday morning i found out of his and mine best mates that he was acctually cheating on me with his ex Ricky. All i want to die right now and even tried killing myself on monday night. I don't have a clue what to do anymore i feel emotionless and worthless. Someone please help me!!!!