Injury at work 3 yrs ago?

I was helping a patient get from her wheelchair to the bed. She was unable to help and I had to turn her to get on the bed. I felt a major pull and pain in my right lower back..I went to the doctor and then rehab for 6 weeks. I was fired from my job and didnt think they would pay my bills at that time. I continue to hurt and get shots to releave pain and now 3 yrs later my doctor said I will never nurse again. Im unable to lift now. Would I be able to sue the company at this time...