Hello and welcome! I would think your suggestions as to causes might have some merit. I'm wondering, too, if this speech wasn't real important to your grade in the class, so you found yourself getting keyed up about that--or that you really don't like some class members and/or the professor?

As you say, it is sort of strange. You might want to talk to a school counselor about it, so you won't worry about it in the future.