Check for diverticulitis. It affects most people on the left side that you mentioned, and untreated can cause fever and other problems. Also, the hardness in your abdomen points to possible constipation, another symptom, along with the pain, of diverticular problems. Good luck.   Should you be unable to afford a doctor, which I hope you can, and suspect diverticulosis or diverticulitis, drink plenty of tepid water, get rest, do NOT eat anything seeded -- such as nuts, popcorn, or even tomatoes -- and take an anti-inflammatory. I have also found that eating soft foods and liquids only for a day or two will help to de-stress bowels, intestines and stomach.