I say bring your resignation to your meeting on Monday. Inform them that you have been harassed and humiliated for no good reason, and are no longer comfortable working in such an environment. I would threaten legal action, but it might not come cheap or easy.
Sounds like a vile workplace, which even you have acknowledged. Not worth the paycheque! Time to move on, Simon! Fresh start.
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│ He who dies with the most guns, wins.