How to tell the brain to staahp

Hi there, im texting with a quite young dude atm. He is 18 and im 27 (male). I wrote him because i kinda fell for his eyes and we live very close to each other (~20km he lives in the same place as my parents do). We chatted a lot and also exchanged pictures. We were planning to have a date last weekend, but he mixed up the vacation with his parents, that actually started a day earlier than expected..so we had to cancel that.. he came back yesterday and we chatted today. after a while i told him, that i would be available on thursday for catching up on our date. He said he will save that date but didn't said for sure it will be going to happen.. Well it would be his first date, i think he hasn't even kissed a boy so this is all new for him. I have to admit i'm not dating for so long so i also have a lack of experience.. i am mostly the one who asks questions and push the conversation and i'm not very used to it.. I'm used to be the one with the feel of superiority but this time it is quite different.. In my head I already imagine how it would be to be with him.. not only sexual but also how i would tell my parents that im...in love? I'm thinking too much stuff like this.. at work, at home, when i'm with friends.. and i haven't even met him and should be old enough to stop this kind of bullshit wishful thinking..but i can't stop it. I just needed to get this off my chest and hope it helps to stop my brain from think through all the possibilities, which might never come true.. Has somebody a similar story he could share?