It's just an opinion, but I don't think you should pursue him. Give it a little time and space for him to miss you, because at the rate you guys are contacting each other all the bad memories will upstage the good ones. It's good to miss the good parts of the relationship, and let it be like that. Don't contact him, let him miss you, and if it's meant to be, you guys will get back together.

Just don't contact him, if he's really dramatic he'll try to contact you.

Personally if you're not happy in this relationship, you should let it go. If he's said nasty things, he might very well do it again and take you for granted. The whole hurt cycle starts again. That's what's happened to me before. I should've just left when I had the chance.