Unless the sense is that my peers (and/or teachers) accept me; then the present simple is fine.
I put "I was accepted by this school" (I was interpreting it as my application to study there was accepted) but was marked incorrect. Could it not be interpreted that way also? Or does it mean more specifically that I was accepted among my fellow students?
I think so. I wrote "accepted TO the school" which has the same sense but was also marked wrong.