How do I get out of the terrible habit of thinking too far ahead in an early relationship?

I just want to live in the moment and take things day by day in an early relationship. The problem is I set unhealthy expectations psychology by thinking too far ahead and coming up with scenarios in my head. I need to get out of this habit bc as I’ve noticed I tend to fall for the potential, instead of focusing on what’s right in front of me. It feels like that old cliche, “you’re not in love with her, just the idea of her” I’m a fairly young college guy, and haven’t been in many relationships but i don’t want to carry the current mentality I have going into future relationships. After even a date or two I’ll think too far ahead and don’t know how to stop.