Give space: If the other person suddenly becomes cold and doesn't reply to messages, it may be because they need some personal space. Constantly sending messages or trying to contact may aggravate their sense of resistance.
Reflect on communication style: review your previous communication to see if it is possible that some topics or information caused the discomfort of the other party. Sometimes, people will choose to back down because of misunderstanding or uncomfortable topics.
Maintain self-esteem: Although you may want to continue this relationship, it is important to maintain self-esteem and not sacrifice your value and dignity in order to pursue the attention of the other party.
Direct communication: If the situation does not improve, you are still confused about the other person's attitude, so consider expressing your feelings directly and politely. Choose a suitable time to tell the other person that you have noticed their recent changes and ask if everything is all right and if there is anything you can do.
Be prepared for the result: after trying to communicate, there may be many results. The other party may honestly explain the reasons or keep their distance. Whatever the outcome, it is important to accept and respect each other's choices.
Pay attention to yourself: No matter how this relationship develops, the most important thing is to continue to pay attention to your growth and happiness. Investing in personal hobbies, study, work and friendship are all important aspects to support your growth and maintain a positive attitude.
Seek support: If you find that this situation has a great influence on your mood, you may wish to talk to your trusted friends or family, or consider seeking professional psychological counseling. Sometimes, outside opinions and suggestions can help you better understand the situation and find the way forward.
Remember, although you may feel sad now, every experience is a part of growth. Keep an open and positive attitude, I believe you will find your own happiness.