First of all, I understand how you feel now. This situation may make you feel very painful and frustrated. However, we need to face the reality and take active measures to deal with this situation.

First, you need to reflect on yourself. Why did you agree to give it to him easily without considering the possible risks and consequences for the first time? This may be because your views on sexual behavior are more open and casual, or because you have deep feelings for him and are willing to make any sacrifices for him.

However, it also reflects your lack of understanding of self-protection and self-worth. When dealing with emotional problems, we need to keep a clear head and an independent attitude, and avoid making decisions that we regret because of a temporary impulse.

For the current situation, the following measures can be taken:

Communicate with him: First of all, you can try to communicate with him and find out why he changed his mind. Maybe he has some internal reasons or pressures that prevent him from continuing to maintain a relationship with you. Through communication, you can better understand your emotions and coping styles.

Accept the reality: If the fact is that he has fallen in love with someone else, then you need to accept this reality and realize that you need to leave him. He is not the only thrill for you, and the affection between you is not irreplaceable. You need to focus on yourself and pay attention to your growth and development.

Self-protection: No matter what you decide to do, you need to give priority to your own interests and dignity. You need to maintain an attitude of self-respect and self-protection and don't let yourself get hurt again. Including avoiding too much contact and entanglement with him and paying attention to your physical and emotional health.

Seek support: Finally, you need to seek support and help, including communication with family, friends or professional psychological counselors. They can provide you with emotional support and advice to help you get out of trouble and restore your confidence.

In short, in the face of this situation, we need to maintain a calm, rational and self-respecting attitude and actively take measures to deal with and solve the problem.