Harassment/Retaliation/Discrimination-Forced to stay on job

As a news reporter under contract I find myself in a situation where I'm being retaliated, harrassed and discriminted against at work. I would just leave--- BUT here's the twist- my company WON'T let me out of my contract. I'm being forced to stay in this extremely unhealthy work environment!

I find it extremely difficult for me to do my job and I feel they are hurting my professional reputation.

I did not have ANY discipinary problems until I filed a complaint with my supervisor against a manager who was verbally abusive and threating. I asked that the complaint be sent to HR but recently found out it never was.

The situation has escalated since I've asked to be let out of my contract several months early.

They flatly refused to let me leave and since then one of my bosses is accusing me of lying about several things... (I have proven him wrong on on all of them.)

He has taken me off of key assignments. Does not allow me to do stories on my assigned "beat."
Now requires, for the first time, that if I call in sick I need a doctors note ( not company policy)
Has called at least one of my story contacts to check up on me to see if I was lying when I said I couldn't do the story on that day( The contact called me concerned wondering why my manager would question me. )
I'm now randomly on some days being assigned to work in a different office 70 miles away-drive my own car-which is not standard.. and they are forcing me to work overtime... to name just a few things. NONE of this was done before my complaints. And the manager in question has also told me recently I need to get "Mental Help."

When I contacted HR with these complaints they "investigated" but said my boss denied all allegations. That it's "He says She says." I didn't expect anything more I just hoped the investigation would make them back off.

When I brought in a tape recorder to record a conversation with HR about the investigation I was told by I could not bring a tape recorder or anyone else with me for that meeting or any other with a manager.
I asked how I could ever prove "who said what" and was told I couldn't.

I want to be left alone to do my job in the time I have left. What recourses do I have if any?

I feel trapped in an abusive situation. Most people worry about getting fired..I worry about what they will do to me while they make me stay.

Thank you so much for any help!