Is it normal for my ex to be hung up on me for this long?

I left my ex back in 2012, and still to this day this mofo stalks my Facebook, makes fake profiles in attempts to befriend me (then goes on about suicide, self harm, etc), actually attempts talking to me about his feelings then insults me when I won't essentially fall back in love with him, and asks my friends about me. Recently he messaged a friend of mine about me and it creeped her out to hell because she and I hardly show public displays of friendship, but she happened to become really close to me at the time. He even told me his therapist says he has a "psychological hold" on me. That was like a year or so ago though.

A little backstory on our old relationship: We were both late teens, he was a man whore, while I was someone in a shitty relationship that was filled with sexual build up. I hadn't had sex with that boyfriend in 2.5 years but he sexually frustrated me on purpose. So I met my ex and we clicked in a way. Left my boyfriend for him and knew he was a man whore. We made a deal that he'd be my first and that was that. Well we started to like each other for some god awful reason. He was instantly clingy, wanting me to meet his parents. He then got really critical over my body, the way I ate, the people I hung out with. He was paranoid I'd have sex with other girls, for gods sake. Anyway, we had sex. Lived out our relationship, he cheated on me, ignored me then dumped me and I moved on because why shouldn't I? Well he was upset that in moving on I slept with another guy. He was furious about the fact another guy stuck his dick in me. Even though I wasn't dating him. Ever since then he has been watching me and virtually stalking me. I've tried being friends, I've tried even being friends with benefits and this kid is too damn crazy and possessive. Oh, but he can fuck around. Forgot that part. xD