It's good to seek advice of another's point of view in this situation.
Just moving in isn't the answer unless that feels doable.
My guess is: you may be filling in the blanks of his desire towards you with how you want him to feel about you.
Do you think he's seriously interested in developing something with you?
If he's shut off or shut off from you, that says something.
From my own past experiences,
I've tried to WILL guys to be interested in me.
I wanted it SO much, however, they do what they want to do and there's no manual that explains their actions.
He sounds vague and questionably caring about you.
At 18, it may be difficult to realize what a promising interaction may look like, or more importantly, what it feels like.
Have you asked him if he just wants 'company' right now and not have the pressures of a relationship?
It may not be your immediate goal, however, you'll know where he stands.