Most Helpful Guy
Most Helpful Girl
If you have no intentions of getting back together then give each other some serious space.
It sounds like you both are frustrated with how things were in your relationship and now that you are not together you are taking jabs at each other for how the other person was wronged in the relationship.
Instead of fighting, I would just give him some space. He should also give you some space.
Keep yourself busy with friends and other things that will help you forget about it.
Give yourself time to heal. I personally do not see the point in keeping the lines of communication open after a break up if it was a bad relationship.
I'm not saying that you guys can't ever be friends. But it's not helping your friendship if you are taking jabs and making each other resent the other more.