How Can Swelling And Pain On The Back Be Treated?

I had a fall 4 weeks ago, I landed on a wooden stool on my left back area. X-ray and Scan showed no damage to kidney or pancreas, however, the area is still swollen and painful. I cannot sleep on either side without extreme pain and last Tues I started having a low grade fever and severe diarrhea. I m thirsty all the time but water or liquids go through me and turn into diarrhea. Recently my legs started feeling like they are having muscle spasms down the back of my thighs and calves. Is it necessary to see my Dr or could it be just residual affects from my fall?