Good day. i just want to find out what this could be. i woke up this morning, feeling nauseous, had a headache. slight fever(37.7) uncomfortable pain above my navel, and lower back pain. also have no energy or appetite.

Hard to guess: A fever is a body temperature at least 1-2 degrees (F) above normal, caused by chemicals released during an infection (most common cause) or during an allergic reaction, an auto-immune reaction, a drug side-effect, etc... An abnormally high body temperature from over-dressing or getting overheated on a summer day is usually not called a fever. One's primary care doctor can check it out.