Go to the doctor. Based on your symptoms, nobody here will be able to give you help without a diagnosis. Make sure they test for everything including Lyme's disease when you're there.
I am sorry to know about your health. There can be several causes of this nauseous feeling like gastro esophageal reflux disease, gall bladder disease,migraine,food intolerance, food poisoning,gastroparesis,vertigo,meningitis,space occupying lesion, hepatitis etc.What are the other symptoms you have been having? Generalized anxiety disorder, panic attacks are few other possibilities. You can try taking light food .Avoid oily, greasy foods. If the feeling persists seek medical help. A complete history, clinical examination and investigations will be really helpful. Tests like endoscopy, liver function tests, ultrasound abdomen, and CT scan brain may be needed depending on your clinical findings. It’s really been a very long time since you have been having these symptoms so it is better to schedule an appointment with a physician ASAP. Do write to us again with more information on your condition. Hope it helps.