Did Congress legislate to censor your newspaper, or did the school administration say "You can't print that!" I'm going to go ahead and assume the latter.
I'm assuming the paper was being funded by the university? It's not that your right to free speech was being suppressed, it was that no such right applied in that situation. You had the right to say whatever you wanted, they had the right to not have you say it in the paper they're funding or allowing onto school grounds, etc?