For the last 3 weeks or so i've had only intermittent appetite, and, whenever i eat, i feel full for far too long. is there anyway this isn't serious?

Could be anything: The symptoms you describe could be caused by anything from a temporary viral illness causing some irritation, to a more serious problem such as an ulcer. See your doctor for further evaluation and treatment recommendations, and in the meantime, avoid things that can aggravate the stomach: alcohol, caffeine, spicy/acidic foods, stress, aspirin, NSAID meds such as Ibuprofen or naproxen, etc.