Jealous ex ! How do I move on?!

My ex (we have two kids together) treated myself and our children like we weren't important for years!! 6 years later I finally realized I could do it without him and I left him and kicked him out. The first 8 months of the breakup he went wild, had many girls, hardly came to visit our kids, but made sure to msg me daily and emotionally abuse me . Once his fun was over he begged for us back to which I wouldn't give in because by then I got my shit together and was ready to let loose. Now my ex stalks my fb, yes I've blocked him but he uses he's friends or fake profiles to see who likes my photos or who I am friends with, then he msgs the guys to ask what's going on between us (even if there's nothing happening, or were just talking as friends) reminds them I'm his "baby mama" tells them we are on and off all the time and that I'm not nice, I'm angry, blah blah. I found out today he's been msging these things to someone I'm talking to, he found it suspicious because he saw this guy like my profile picture which obviously any fb whether friends or not can see. How do I deal with someone so jealous??! I can't bring this up to him because the guy doesn't want drama, which is part of the reason why we don't hang out or spend time is because we both don't want the drama from my ex and I definitely don't want fights or threats flying around just because someone is interested in me. I feel like packing our lives up and moving away somewhere fresh, it feels like because I don't want him he won't let anyone else have me and I hate feeling like I'm doing wrong when I know I am definitely not! Anyone else been in this situation??