What causes fatigue and indigestion?

Lots of things, C MD. Indigestion and fatigue are both nonspecific symptoms. Could be lots of things, e.g. Ulcers with bleeding which cause iron deficiency which leads to fatigue; could be hepatitis which leads to above; could be gyn issues; could be depression . Can't tell here. See your doc.
See a doctor. Indigestion is not a medical term. When people say indigestion, they usually mean discomfort in the stomach area during or after meals. Or a feeling of fullness after eating small amounts. You may have something as benign as viral illness, gastritis or acid reflux. But it could be something as serous as delayed stomach emptying from another condition, an ulcer or a mass in the stomach.