Join a union and ask for their advice. Even if there's limitations on what they can do as it seems the process has already started, they'll still be able to advise on what you're able to do deal with constructive dismissal.
Look for another job. It's way easier to find work when you're in work and don't have to explain why you're not at your last job.
Do both of these things. Your health isn't going to benefit working at a place where you're not wanted, even if they can't just fire you.
Oh and if you're in a country where you're allowed a representative in meetings and you can take one, always have your union rep there, no matter how friendly it seems.
When your villain origin story is getting banned from a truck simulator mod because you forgot the macro to turn the headlights on.