I don’t know that my advice is very useful. I had a bully after me in middle school and I channeled Mr Spock. I schooled myself not to react or to make sarcastic comments that had others laughing with me at the bully. Star Trek was my favorite show and Spock my favorite character. It started with just schooling my physical self not to react. Over my life I’ve become slow to react to bait and that gives me time to think. Is their maybe someone in your life who you admire the way the handle such situations and that you can try to emulate?