Sudden right sided pain abdomen?

Let me first note I have a high pain tolerance. Very severe pain in my abdomen woke my up at 4:30 Friday morning. It went across both sides a couple inches below my rib cage. It was extremely debilitating (walking was very difficult) and it would get EVEN worse for a few minutes at a time. It was still really bad at 10 am. By 11, it was getting a little better and was only on my right side. That night it was still bad but not as debilitating but better if I didn't move around. By then, it felt that something was swollen and squeezed if I leaned on something on the right side. Today, 36 hours later, it is much better but still sore to the touch and moving exacerbates it. Eating, on the other hand, has absolutely no effect at all. I have no gas, I've had normal BMs (although I did have diarrhea for a couple of weeks preceding with possibly some mucus - not sure). I've also had severe itching (probably unrelated) for about a week-10 days before this started (which began 1 week AFTER taking Avelox for a sinus infection). Hope that's not too much info but I don't have insurance and have no intention of going to the doctor. I've had this at least one other time and I know it will go away but it sure is debilitating when it happens. Otherwise, I've had no other gastric problems unless I've just ignored them (very possible). Come to think of it, I probably have had more nausea and stomach discomfort in the last 8 months but not bad. PLEASE someone offer advice, preferably someone with a medical background.