It sounds like you're going through a really tough situation, and it's completely understandable to feel confused and hurt. Let's break down some of the key points and emotions you're experiencing.

Understanding Your Feelings:

Having strong feelings for someone can be overwhelming, especially when those feelings persist over time. It's normal to fantasize about what a relationship could be like, but it's also important to recognize when someone's actions are negatively impacting your self-esteem and happiness. You mentioned that he is the only person you think about, which can create a sense of attachment that is hard to break, even when the reality of the situation is painful.

His Hurtful Behavior:

The way he has treated you—making fun of your appearance and mocking your interests—is not just inconsiderate; it's downright cruel. It’s important to remember that someone who truly cares about you would never belittle you or make you feel bad about yourself. The fact that you've changed your appearance and lost weight because of his comments highlights how damaging his words have been. This is a clear indication that his behavior is toxic and not worthy of your admiration.

The Confusion of Mixed Signals:

Seeing him flirt with other girls while simultaneously giving you uncomfortable looks can be incredibly confusing. This kind of behavior can lead to mixed signals, making you wonder if he might have feelings for you or if he enjoys seeing your reaction to his attention. However, it’s essential to focus on his actions rather than your interpretations of them. His actions—mocking you and flirting with others—are not signs of genuine interest.

Moving Forward:

As he prepares to leave for another school, it might be an opportunity for you to create some distance and begin to heal. Here are some steps you might consider:

• Reflect on Your Worth: Remind yourself that you deserve to be treated with kindness and respect. Surround yourself with friends who appreciate you for who you are.
• Focus on Yourself: Use this time to explore your interests, build your confidence, and embrace your individuality. Whether it’s through music, art, or sports, find things that make you happy.
• Talk to Someone: Sharing your feelings with a trusted friend or a counselor can provide you with support and perspective. Sometimes, just talking about what you’re going through can be incredibly relieving.
• Set Boundaries: If you have to interact with him in the future, consider setting boundaries. You don’t have to engage with someone who doesn’t treat you well.

Conclusion:

Remember, what you're feeling is valid, and it's okay to prioritize your emotional well-being. The right person for you will appreciate you for who you are and will never make you feel less than you are. It can be hard to let go of a crush, especially when it feels deep, but with time and self-care, you will find clarity and peace.

Take this experience as a lesson in recognizing your own worth and the kind of treatment you deserve in relationships. You are strong, and you will get through this.