What do i do???

I work as a press operator at a well known gasket company 12 hrs a day. The machine that I was working on begin to have problems such as the die kept getting stuck going in and coming out. When mentioning to my supervisor the problem he checked it out and said " yea there is something wrong with it and i'm going to have to call it in to be fixed". Well after him saying that I asked "should i still run the jobs" and he told me "yes". The next night i arrived to work the machine was still doing the same thing and i ended up hurting my back. I went to their company doctor where i was diagnosed with an acute back sprain and spasms. Upon this i have been assigned to light duty however, the supervisor has begin to go around asking co-workers that work at machines next to me "am i really hurt?" Any advice on what i should do?