Im having pain in my back ankle and head

[Shelisec]

So I have been having back pain almost more so burning pain which is now spreading into the back right side of my head and going as far down to my right ankle my ankle also is swelling up and is sometimes very painful .. the pain in my head isn't as back except when I cough or sneeze it feels like there are hot pins shooting through my head to the back of my eyes and some times my sciatic nerve flares up in pain to...  I went to the emergency and they did absolutely nothing at all except give me a shot and some muscle relaxers but that was it and sent me home with in a hr did no testing no nothing at all please help me try to figure out what is wrong any suggestions will help