discriminated against due to my weight

I feel that I am being discriminated against due to my weight, my wages are min. 10,000. less/year, (same job title, great reviews).
I have been out of work on a worker comp claim for the past 6 weeks. I was released for work and will be returning for ½ days. My boss wants to place me in a different office making phone calls, and keep the temp to cover my desk. I feel that this is just another way for me to be brushed aside. When I spoke with personnel, they said “because I was out when they needed me they hired a temp and do not want to move the temp around, that it wouldn’t be fair to them.”
I feel like I’m stuck with little option but to be placed in another job. What if any legal options do I have?