How do I stop getting attached too soon?

I feel so stupid. I’ve fucked up two possible relationships because I felt so strong about them too quickly. I know it’s just infatuation, but it’s such a strong emotion. This guy that was talking with me said that he was just flirting with me, and didn’t want anything more to do with me. I hated feeling like that. I wanted so much more. I thought about a future with him, but he didn’t even like me that much. I feel betrayed, but I only knew him for a week and a half. How do I stop being a bird and start dating regularly?