Long term, sporadic, severe to low stomach pain. Sudden intolerance to alcohol + sugar, frequent urination, irregular heart rate. Pls ease my worries!?

Not certain we can. ease your worries as your symptoms could potentially be due to a number of different conditions. You need to see a health care provider for an examination and laboratory testing to evaluate the significance of your symptoms.
Doctor can evaluate. Recurrent symptoms need evaluation, because something is wrong. Lots of things are in or near the "stomach" area, such as the stomach, small and large intestines, pancreas, gall bladder, kidneys, etc... Possible pain causes include pancreatitis, gastritis, stomach or duodenal ulcers, gall stones, cancers in any of the organs in the area, stomach / intestinal / gall bladder infections, etc...