Do I Have Grounds For A Lawsuit?

I feel I am being retaliated against at work. I feel I am being subjected to what is called a Constructive Discharge. I took leave a week ago for medical reasons being related to a horrible back sprain and other medical issues, and my boss changed my work shift and made my work harder than I normally did it for 10 years. This change was only done to me and no one else. I work in construction and its a huge factory with over 200 employees. My boss basically made it impossible for me to work as he changed my shift from daytime to night, knowing I have children in daycare during the daytime hours. He also told me that he expected me to do the work of other employees that I normally did not do prior to my leave. I feel that he is retaliating and forcing me to quit as he priorly agreed to my daytime shift for as long as I worked there. He also seems to be opposed to light duty work status. If I have to quit do to this is there a suit I can file and is it possible to get unemployment if you are forced to quit your job? I am in Kentucky, but my job is in Tennessee.