fwb w my ex

my ex and i have been fwb since we broke up. and we’ve been hu for a year and a half now. i lowkey wanna break it off because i mean i want a relationship but also i don’t wanna break it off cause i get scared of being alone. (ik that’s a bad thing) but every time i try to leave i get extremely lonely and end up hitting him up again. plus he isn’t very nice to me, he treats me badly and takes advantage of the fact that i will go back to him. i don’t know how to stop myself.