What's going on with my friend?

I've been friends with this guy for nine years.  We've always gotten along for the most part besides the odd argument that any friends have. We ended up hooking up one day back in August  I of course thought it went well.  Later on he told me he wasn't interested in a relationship I told him that I understood and we agreed to remain friends.

In November he pretty much stopped talking to me at all even when I would wish him a Merry Christmas or whatever.  On Friday he decided to delete me off Instagram without giving me a reason.  I tried messaging him through Instagram asking him. "why did you delete me? I would like to know if I did something wrong if so I'd like fix it because I truly appreciate you as a friend."  He reads my message but doesn't respond and instead blocks me.  I try calling his cellphone but he already blocked me there too.  As well as facebook and snapchat.  I of course give up after trying to contact him any possible way I could think of.  

I know this is very clingy and unnecessary but I was in a complete panic mode, and I really didn't want to lose my friend.  I ended up writing this message to him that I will always care about him and if he's going through a hard time that he can talk to me but if he doesn't want to be my friend that I understand.  

Then today I get a call from the police that I've been harassing him and he wants nothing to do with me.  Like why couldn't he just tell me instead of being a coward?