IF you REALLY WANT to, you can give boys very clear messages by ignoring them.
But this can only work if you are really clear on what you want. The problem here is that you are saying one thing but giving over a different message through your actions, body language, etc.
You will not be able to get rid of him until you have convinced yourself that it’s what you want to do.
That is why you need a therapist ASAP to help you to figure out how you feel about things.
Meanwhile, at least stop giving him rides and stop talking to him.
Maybe you should consider switching to an all girls’ college.