Breakup

My ex and I broke up a month ago and the breakup has destroyed my head, i have mood swings, I've had suicidal thoughts, I've literally gone numb to emotions and then all of a sudden I'll be hit with huge waves of sadness and anger. He was my first love but I genuinely don't know what to do with myself or how to cope with him ending it. He's going through a lot so he's begged me not to leave his life but it's hard being just friends with someone I love so dearly and who was a huge part of my life for so long. Has anyone got any advice on moving on or coping because I feel so broken and don't really want to be here anymore because I'm not me, my personality has gone and i can't take it