Disclaimer: When I use she/her to reference an ex it is implied that I am referencing both genders.
A couple years back I vaguely remember reading a scientific article out of some major newspaper such as the WSJ or New York Times. Effectively the article stated that after a breakup, women have more intense reactions, but they manage to get over the relationships faster. Meanwhile, men have more subdued reactions but it takes longer to get over their ex. Being a male, I don't know if this is 100% accurate, but what this did make me realize is that we all, for no reason, randomly struggle to get over the relationship as our ex hits us.
Now I don't mean that your ex hits you literally. Obviously, if the person is your ex, you probably want to avoid her so that she won't be able to hit you even if she wants. What I mean is that for no reason at all, you suddenly fall in love with that person again for just a brief moment. It could be a movie you just watched that reminded you of your ex. It could be a certain phrase that someone spoke to you. It could be your favorite food because you introduced it to her and now she loves it. What happens is you suddenly want her again.
All those happy memories. All the good qualities about your ex. You just want them back. The negativities, they disappear and in its place is only blissfulness. TBH, It's like someone just stabbed you in the chest and said "you like her? Well too bad."
I personally have had trouble getting over relationships. It is something about me, I just can't stop loving the other person. Especially, if they broke up with me. So what do I do? Do I scream into a pillow? Do I exercise? Do I listen to my favorite music? All of the above?
No, when my ex suddenly hits me, I hit back. For years I have tried to forget it and move on. I thought that the best way was too ignore the situation and distract myself with the items listed above. While this is a good idea, and I definitely suggest doing it, it doesn't help when you are suddenly reminded of her. You can't distract yourself when she is the first thing on your mind. Instead, I reflect on our relationship and take things head on.
This means thinking about her long and hard, realizing that it's over, and then moving on with life.
You could cry to yourself. You could talk with a friend. You could think about all the good and bad things about the relationship. Its hard because in the moment, you will take a step back. All the progress you have made getting over her is undone. However, in the process you will leave a little stronger. With each breakdown and confrontation, you get closer to the realization that it's over and that there are better things waiting.
No one ever told me that this is how things should be. I have always been told to distract myself when she suddenly crosses my mind. While, distracting yourself and getting busy works in order to not think about her. Once you do think about her, you need to confront it and fight back because with each blow you will get stronger and come closer to the realization that its over.
P.S. I understand this may not work for everyone. This is just something that works for me and I'm sure it can help others as well.