Do you think this is a good idea?

ignore her. don't date her anymore. if you don't think you can speak your words, at least don't let her have the upper hand over your life. you should be the one who masters your mind. block her number. and don't meet her anymore! I would hate to be in your position, your ex is too selfish I think.

Confront her and tell her exactly how you feel. All thr best.

Just tell her that you can't be nice to her anymore tell her just to move on with her life and to stop making your life miserable by behaving as if nothhig happened and then just delete her number email and stuff like that

i would just stay away. don't waste your time. ignore her and delete her from your life.

If you want to talk about the break up and the relationship and her behavior during that, ask her if she's willing to meet up to talk since you have some things you want to say. If she doesn't want to, ask her why, if she doesn't give a good reason, tell her again you need to get some things off of your chest.
If she really doesn't want to, tell her that you want to be left alone for a while, since you need time to get over her and the relationship you had. If she doesn't get it and keeps texting or/and calling you, ignore her and if that's hard, block her number.

Good luck!