Give some advice: my ex-girlfriend sent a text message after we didn't contact for half a year, saying: I feel very uncomfortable and want to talk to me. What should I do?

Two questions: first, do you still feel that way about her? Do you still love her? Second, you don't have a girlfriend now

These two questions can help you decide what to do. In fact, there is only one principle. Don't let yourself regret it later. If you have no idea about her, talk to her as a classmate, or help her. After all, she is still a classmate. But don't forget, she is a married woman.