Suggest Remedy For A Muscle Pull

Hi, this past Wednesday my friend jumped on my back wanting a piggy back, I am 110lbs and she was 140. Ten seconds after being on my back it felt like my top half of my body was pushing down on my lower half. It twisted and cracked, I instantly had a pinched nerve in my back and my left side of my stomach just under the rib cage had a bubbly feeling and now is soar feels like a ball of pressure deep inside. There is nothing I can actually feel as in a lump but my insides feel funny. I could just be a pulled muscle or maybe something worst. I have no idea. Please help.