I have abdominal pain on my left side, i am very tired and nauseous. my tummy is also swollen.

Multiple items: You would need an exam to go along with more history. Fever, chills, change in stools, blood, mucous? Could be left colon (colitis, diverticulitis), an ovary, infected tube etc.

Diverticulosis: Pain on the left side could be caused by a condition in the colon called diverticulosis that could be simple or it can get complicated by infection and bleeding for a female could be an ovary problem or a bladder problem see a doctor for assurance

See MD: It's very difficult to advise based on those symptoms. Many conditions can cause them. Could be constipation, viral gastroenteritis, UTI, STD, pregnancy , mononucleosis and many others. I'd see a physician for a proper diagnosis.