Can I sue a homeless shelter for neglect, even if time has passed?

In 2011 I was living at a homeless shelter in Bangor, Maine. (I'll provide the name of this institution later if shown interest). I fell from a pull-up bar and ended up fracturing my neck. The staff at the shelter laughed, and told me I'd be fine. When I asked to be brought to the hospital, (parts of my body were numb, and I was in excruciating pain) they tried to talk me out of it. Eventually, I was driven to a local walk-in clinic and dropped off by myself, I was 18 at the time. Upon finding out the extent of my injury, the staff at the clinic were amazed that I was not paralyzed, and I was transported by ambulance to the area's major hospital. I didn't sue them out of fear of losing my only home, but I now live in constant pain and thousands of dollars in hospital bills. What can I do?