is this harassment?

LO
Okay so in highschool this boy who I talked to once (Him: "can I borrow a pen?" Me: "yeah of course, keep it.") claimed he loved me and told everyone he knew he loved me. Then he made a giant scene and asked me to prom (where I am from we don't have proms for every grade like Americans do. We have grade 12 prom, that's it) it was very awkward and I had to turn him down because I was already going to prom with my girlfriend. Flash forward 2 years. 
For the past 5 months he has been messaging me on Facebook. Daily. Every day. It's been mostly one sided, at first I'd reply here and there but I felt like me replying gave him the wrongn impression because he would constantly ask me on dates. I made it more than clear that I wasn't interested and then just stopped replying. It's been 3 months now since I stopped replying and he is STILL messaging me daily. 
He's now taken it upon himself to figure it where and when I'm doing things and then message me about it. I don't post to my Facebook anymore because of this but he is still finding out where I am and what I'm doing. He also has messaged me saying "hey I think you changed your number I've been texting you" He has been texting the number listed on my Facebook which is from grade 6 and he has also started emailing me! 
He's created a scenario in his mind that we are together and is posting about it on his own Facebook. 
I don't know if this is harassment or what. I also don't know how to address this or what gave him this impression. 
I assumed after highschool he would drop it, I thought it was just immaturity but this is turning into a real problem and I'm worried when people tag me in things because he will know where I am in that moment. 
I don't want to be mean or do anything to extremely anger him, if I blocked him he would know. I can't just keep ignoring this though. I'm at the point where I want to delete my Facebook, make a new one under an alias and move out of my city (very small city, everyone knows everyone) 
 
Any suggestions?