I am wondering if I have any legal rights for a problem. I have been a state employee for 17 years and with the hiring of a new boss have endured 5 years of mental and emotional abuse from him. I know I have not much grounds for any kind of legal help with this but can my boss take me out of a job I have been doing for all of these years and place me in a job where I am unloading trucks and freight all day? I have now been on my second back injury since July when I was placed here. Do I have any legal rights? I am forty years old with no prior lifting in my last job.

Unless you are being singled out for a legally protected reason such as your race, sex, religion, etc. it is not illegal. As a state employee there may be additional rules unique to your agency, division or union that address transfers and job duties. For that you will need to check with your union or HR.

So even if my boss is putting my physical health in jeporady by putting me in such a hard physical job there is no law to protect me? I can continue to do the work to retain my job and put myself at risk for a physical disability. 3 doctors have said that I cannot do this job so basically I can be forced to quit if I cannot perform the job I've been put in against me will?
He has manuavered this all to get me to quit in the first place so I guess he wins.Could I win any kind of lawsuit with a hired attorney?

In essence if you can't do the job any longer, then your options are somewhat limited. If you qualify for ADA you can request a reasonable accommodation. Not every medical condition qualifies though. If it doesn't affect a major life function and only precludes you from doing this job, it would not count. Also, if heavy lifting is an essential function, they do not have to exempt you from it. They may provide a back brace or a cart or some other assistive device.

If ADA doesn't apply then your option is the same as anyone else who can no longer perform their job. You can seek a transfer elsewhere or another job entirely.

I was released back to work by my doctor with restrictions. If I work another job and I am meeting those restrictions and have doctors approval for the job duties I am doing can I be denied benefits from my main job if they haven't taken me back yet?

You would still get medical benefits for the injury. Whether you would be entitled to TTD or TPD depends on a variety of factors.