Of course, you don't have to have any more classes with this man, right?
So, don't sign up for any more with him, and you probably won't even have to see him, unless he has coverage in one of your classes due to a teacher absence, right?
Some times, things can be very, very simple.

And just as a clarifying question, you said, "if things go too far..."
Well, since he is blocking you and your friends,
Just *what* is going to go too far?
Sounds to me like he's trying hard to stay away; to maintain boundaries.

So, if you are going to seek help from an adult,
What exactly are you going to seek help about?

From what you've disclosed, (which is all we know here), he's doing nothing unprofessional. Indeed, he's being quite professional. (I'm a teacher, by way of complete disclosure.)

So, is it your own feelings for which you you will seek help?
And if not, exactly what?

I'm asking, not for my own gratification, but, for your own clear mind. It still sounds as if you are confused about this whole issue, even though you say you want it over. And the upset at home may be making the entire situation more confusing.

I'm no shrink. But, I've been working with adolescents, in education, for over 20 years. And too many times, things get twisted up in our minds, even when we get older too!

So, really think about what you would want help about. Him? Or you?
These are important issues to discern. A bit of introspection, (internal inspection of the heart and soul), would do you well.
We're here to help if you want to work it out.

Peace!