Help! Relationship life

My ex and I broke up in October of 2016. (Beyond devastated) We didn't speak for a month then when we did he would pick me from work and drop me off home when I needed him to. In January we had sex....then again a few times after that then stopped talking.

Long story short. We don't speak because the lady time we had sex he disrespected me(that was a month ago). Now it's June I hear that he's talking to someone we went to school with. Every time I think about him my heart literally breaks into pieces. All I'm wondering is what do I do? How do I go about things?