I'm going to get angry and throw very personal insults when my ex is antagonizing me
Why do  you want to personally insult your ex?
The fact that she cheated on me multiple times, I did love her very much.
It seems that your ex girlfriend is trying to get a reaction out of you. You should not allow her to push you to the point that you have to respond negatively. Instead, you should walk away to show her that you are no longer interested or block her phone number if she calls or messages you.
I don't care if she is trying to get me, I will get her by going with insults and maybe new things.
Although you are still hurt by her actions, you shouldn't enable her to see that she still has a hold of you. If you react emotionally, she will see that you are still affected by her. If you don't allow her to push your buttons, you will have the upper hand.