I get angry when my classmates approach me, is that normal?

I don't know why, but this only happens when my classmates try to approach me, I'm just sitting doing whatever and some person approaches me and tries to ask me a question or just talk to me, and for some reason, i turn into a cunt and just yell at them "i don't know! leave me alone"
there's this one time i almost stabbed my classmate in the hand with my pencil because she tried to pick up my paper. i felt so bad after it.
could i possibly have anger issues or someshit?