I had a problem with my girlfriend and just sent me a text message saying; Let's calm down. What do you mean?

It means that everyone should calm down and think about how to deal with this contradiction. Judging from the short message, your girlfriend is still very rational and unwilling to expand the contradiction, so she put forward this suggestion. In fact, communication between men and women cannot be without conflict. The key depends on how to deal with it, whether it is heat treatment or cold treatment. Many contradictions are actually not serious, just because of anger, which leads to more and more contradictions, so it is good to deal with them calmly. If you encounter a contradiction that can't be solved at the moment, you may wish to put aside the dispute for the time being and wait until you calm down. We won't make a fuss about small things just because everyone is angry. I suggest taking your girlfriend's advice and dating her as usual. After a period of calm, if you feel that it is your own problem, sincerely apologize. If it's the other person's problem, communicate and convince her.