Beaten and verbally abused by 78 year old grandmother

I went over to my grandmother’s house to bake her cake for her 78th birthday. After taking over 2 hours to finish it, she remarked that it was “too soft.” I got annoyed and said “maybe you ought to appreciate your grandson taking the time to bake you a cake.” She looked at me and said, “maybe you ought to shut the #$% up, nancy boy,” and then hit me in the face with her cane. The next morning I had a horrible headache and a slight black eye. I went back to her house the next week to ask for help with my medical bills, but she kept cursing at me and telling me to “man up” and “walk it off fat boy” (I’m 6”3’ 250 lbs). She also calls me “Sally” and other female names. So now I’ve got a huge medical bill and recurring nightmares of my grandma beating me with her aluminum Sears cane. I’m so humiliated I even told the guys at work I got the black eye fighting off a mugger. Should I take her to court? Could she go to jail? I’m telling you, she’s sharp as a tack and knows exactly what she’s doing.