Patience issues / I feel ridiculous

Oh my god, where do I even start. Okay, so my ex left me about two weeks ago, all of a sudden, with no reason. I know now that our relationship was becoming toxic, and I understand that. I don't understand how someone can say they don't want me out of their life after they leave, then proceed to ignore me and erase my existence. I do not understand that. I also do not understand how someone can have another person wait on the sidelines, as they decide whether they want me back or not. I love him, and I want him, but he is being cruel, and I am not sure if he realizes it or not. Any advice would be extremely helpful, please.

First off I'm sorry you're going through this. Keep that chin up though. Seems to me you have two options, ignore him or fight for him back. Ignoring him and moving on will most likely be better off for you in the long run. If you want him back, go to him, demand an answer, tell him how you feel. Be honest. Make him hear you out, and if he still feels the same way, walk away and do not look back. You did all you could, no regrets.