Can anyone help me with rib pain and terrible sickness?

On Tuesday I was just about to go to sleep when I had rib pain which was so painful I couldn't move then from it has gotten worse and worse except now I constantly feel sick and last night I was hanging over the toilet waiting to be sick but since I hadn't eaten properly for the last two days I couldn't do anything about it. I have lost my apatite and really find it hard to even walk around my house. I have just lay in bed and drank lots of water with a hot water bottle on me and I feel even worse. I have taken paracetamol, pepto-bismol and have just been resting. I have no idea what i have done but all i can say is the pain is like someone is pressing down on me and theres a bad aching feeling making me bend forward. And theres a stabbing pain in the middle of my ribs, I have been cleaning a lot recently and don't know if i have pulled something however, i do not remember feeling like i had. I have just come off diannete ( the pill ) and roaccutane ( for my skin ). Any suggestions of what it could be? Or how I did it? Any similar problems? I'm 16 today :) and this has ruined my birthday :( Thank-you for any replies.