Ex wants to suddenly talk. Advice?

He's your ex for a reason. Since by your own admission you 'haven't got over him' it'll be asking for trouble to go back out with him, and think it's all going to be lovey-dovey. Plus the fact that you have had two failed relationships after splitting with him, strongly suggests to me that you shouldn't try for another until you are totally healed. Otherwise, it might end up a downward spiral of pain.