Why does my left leg cramp and hurt so much. I also feel a cramp at the abdomen to the side. What does this mean?

Electrolytes. Cramps are usually associated with some type of electrolyte problem and calcium, magnesium or potassium are likely decreased. See if your doctor can check them.
Stretch drink a lot. Long periods of exercise or physical labor, particularly in hot weather, may lead to muscle cramps. Some medications and certain medical conditions also may cause muscle cramps. Treatment, stretching exercise, stay hydrated if dose not help your doctor could help with some medication.