I like him

I like a senior (I'm a freshman). i've known him since I was like 5 y/o. we've been talking for months but it's just getting serious now and I'm falling hard for him. we are supposed to go get ice cream on Sunday (its Friday now) but I'm sooo nervous I dont want it to be awkward. even thinking ab him makes my heart race. ahhh I dont want to fall for him bc hes leaving for college in like 3 months and I dont want to be heart broken. what should I do? sorry if this is confusing I'm personally confused with my feelings.