How to handle missing my bitter ex?

but I was unable to stay with him do to his heavy drinking cocaine habit. We remained friends but still acted as though we were together and that lasted for a week until One night he was SO drunk, he called me then called my one friend, that just...

happened to have slept with over 60 men, to hang out with for 60 seconds. He was so drunk she said he wasnt even making sense doesnt remember. I was so angry, upset and disgusted that he would do that to me, I called him up while he was at work, and cursed him out on his voicemail, telling him to never call me again that he was a pig,disgusting, I was too good for him. Unfortunately we work together, when I was at work I ignored him staring and just being an asshole. 1 weeks later I ended up being admiited in2 a 4 month rehab for prescription drugs. During that time he did not hear from me once. I come back to work has a new girlfriend that also works with us (not for nothing but I am better looking lol) but is just an asshole after all this time and what I went thru constantly stare..I ignore him.

He was bad mouthing me, and I just ignored him, and eventually management got involved bc it was interfering with work. He left me alone SOMEWHAT. I gave him a bday card on his desk to make ammend around thanksgiving. I wrote in the birthday card saying it was unfortunate how things turned out, but I hope one day we will be bale to look passed everything and become friends again I wish you nothing but the best of luck and have a safe and happy birthday! I got transferred to another location for the weekends and he tried getting transferred right after me to my new location but he got denied. I truly miss him...

teh most recent story...
He mentioned something about work 2 me, when he didnt have to, I would have found out that day. And This man was hitting on me about 40 but good looking, right in front of him. it happens, but never in front of him. So the guy had 2 tickets to a comedy show in his hand saying oh come on I wann atake you blah blah...n tom was coming by and he was staring, so I looked at him and he quickly moved his eyes to the tickets and squinted his eyes liek he was trying 2 see the tix, so the man turned around and was liek what the f*ck are you looking at? lol and it was just funny...

All he does is stare at me. I know it is pathetic and I should just move on, but I love him, and I want to gove it another chance. We were at our worst when we were together, I want to gove it a try at our best. How do I get him to stop being so angry? When will he stop? why is he acting like this?

He really doesnt seem worth it. A suggestion on how to handle it is to stay away from him which is hard because of workdatt but yea uno guys treat em mean keep em keen.