I've been involved with a guy, on and off for about 2 years. He's a manipulative, abusive bastard. I was infatuated with him. Finally I have in the last few months felt that I have lost any feelings for him but he keeps on contacting me still. So I sent him a message telling him I never want to see him again and he's treated me like crap by standing me up and giving me chlamydia as well as lying that he loves me. I feel so much better telling him to F off. His response was 'I hope you die'
Should I be worried that this is a threat or just forget all about it?