NEED ADVICE!!! ASAP/ CRAZY EX?

so when i was in hs, i dated this guy FOR A VERY BRIEF AMOUNT OF TIME. when we were in high school he showed me that he might have a few issues, but i figured that he just needed to grow up. anyway, i broke it off, whatever.

so he came back into my life 2 months ago..and he really hasn’t changed much. he’s kinda obsessed, constantly thinking i’m with other guys; etc. i’ve told him time after time that i don’t want him like that, really just want to be friends, but @ this point i don’t even want that. i want to cut him off period. but..like i said, i think he has issues. he knows where i live. i don’t want him showing up to my house, i’m scared of him, tbh. what do i do???