Half a year after breaking up, my lover sent me a text message saying that he missed me. What should I do?

This is a very sensitive and complicated problem, which requires you to carefully consider your feelings and situation. Here are some suggestions that may be helpful:

1. Face it rationally: After breaking up for half a year, your lover contacts you again, which may mean that he regrets this relationship or has some unfinished feelings for you. No matter what you think inside, you need to stay calm and rational, and don't be easily influenced by emotions.

2. Reply carefully: You can choose how to reply to his message after careful consideration. You can reply politely, indicating that you have heard his message, but it doesn't mean that you need to respond to his feelings immediately. If you feel comfortable, you can also choose not to reply or tell him that you need some time to deal with your feelings.

3. Respect the past: You used to be lovers, which may mean that there are many good memories between you. Respect the past and let him know that you cherish this experience, but you also need to let him know that you are an independent individual with your own life and emotional needs.

4. Pay attention to the present: The past has passed, so you need to pay attention to the present and the future. If you decide to get back together, you need to know your feelings and needs and discuss with him how to establish a healthy relationship.

5. Respect yourself: Most importantly, respect your feelings and needs. If you don't want to contact or reconnect with him, then you can choose to stick to your own ideas and not be influenced by others' ideas.

Finally, no matter what you choose, you need to be clear about your feelings and needs and face this situation with confidence and firmness.