i have been in a few relationships with an obsessive man before and i will say that it is a very stressful and difficult situation. if they are at all violent it can be downright dangerous. i know, because one of my boyfriends tried to murder me.
Step2
you need to be consistent in what you say and what you do with the person in question. it is so easy to continuously take them back because we feel sorry for them or its exhausting trying g to get them to stay away, but don't fall into that trap! you have the right to leave someone if you so choose and no-one has the right to take away your freedom.
Step3
if they begin stalking or harrasing you can go to your city courthouse and file for a restraining order. then if they come near you they will be arrested.
Tips & Warnings
if you feel scared of this person you may want to stay with a friend or relative for a bit. or you can have a friend or relative stay with you too until it blows over.