This is not a legal advice either (as I do not know your local legislation), but just a reminder that people who are hurting, easily hurt other people as an outlet. Most likely your worst bullies have shitty home and neglectful parents. This naturally does give them permission to be pieces of shit. This is just a good thing to acknowledge. Keep your chin up high and try not to despair. Keep your parents and your teacher / principal updated of your situation.

Nevertheless, how bad you feel, do not attempt to hurt them back and do especially not skip school (you will outgrown and prospect while they wither). Seeing a professional to talk about your feelings is not a shame either. Most of us have done that at some point of our lives.