It's cliché, but in such situations...
Document, document, document!
Save all the emails and make memos of all the incidents, encounters and meetings.
"HR" is not your friend. Ultimately, their job is to protect the company.
Consider talking to an attorney specializing in labor issues ("labor attorney" or "employment attorney").

Personally, I think it best you leave that environment. Some sort of counselor with labor/employment-issues experience should have a good idea how best to make the transition out.
May this all turn out in your favor.