If you can't calm down because of something, maybe you can focus on doing another thing so that you can no longer be disturbed by the previous things. Aren't many people like this? After breaking up, or losing someone important, they are often busy with their work and have no time to think about another thing. Of course, this is only moderate, otherwise they will get twice the result with half the effort.
When you can't calm down and do things, you can also try to talk to your trusted friends or chat. Maybe with the help of your friends, you can let go of some things and refresh yourself. I met a friend. His condition is that he is preoccupied with everything, especially in class. Other students are doing their best for the college entrance examination, but his eyes are straight every day. From the moment he started studying in the morning to the end of the evening self-study, he left like this. I talked to him, and he said he didn't want to do this either, but he just couldn't help it. His heart is like a mess, and he can't calm down. Later, I found some friends and we became acquainted with him. We talked together in one place. At that time, he told me the reason that had been bothering him. We all tried our best to help him. Finally, he finally let go. He smiled happily from then on, and he can study hard like us and sprint for the college entrance examination.
Of course, if you are always confused and can't settle down to study like me, you can try listening to music, or going out for a walk, exercising, etc., and you can also achieve unexpected results, which is not bad. I hope I can help you.