How Do I Tell My Heart To Pump The Brakes??

Ive gotten attached to the guy I recently started seeing pretty quickly because I’ve known him for awhile so I already liked him, but we are still figuring things out. I don’t wanna freak him out by coming on too strong, and I also don’t want to psych myself out for something that might not happen or make it too easy. How can I stop myself from getting even more attached to him too quickly? 😞