Stop being so dramatic. You only went out with him for four months correct? You were fine before he came into your life were'nt you? If you were then you'll certainly be fine again if you actually give yourself time to heal and help yourself to get to that stage through zero contact.
He duped you. Thats not your fault. It is your fault if you continue to allow him to manipulate you the way he has been. Now you're just volunteering for his crap.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion