I am not able to eat without feeling sick, why could this be?

See your doctor: Nausea can be a sign of many problems, gastroesophageal reflux disease being one of them. Should see a doctor for an evaluation.

2 big possibilities: All of our organs are packed together, so it's hard to tell where symptoms are coming from; however, there are 2 main concerns here. You could have ulcers or stomach acid erosion which is making you feel sick. If you have no symptoms between meals and there is pain under the right ribs when you eat greasy/buttery foods, then it may be time to get a gall bladder ultrasound. Bland diet from now on!