I have been vomiting for the past year and have been getting symptoms of acid reflux. i went to many doctors and have been taking many test. they say it can be psychological but i am fine. what can be the possible cause?

Among many others medical causes, psychological and recreational substance use are to be considered. Anxiety, specifically as seen in PTSD and for example may be involved in cyclic nausea and vomiting as well as recreational marijuana use among poorly recognized causes for symptoms like yours.

It is not feasible to provide a meaningful opinion without taking additional history, physical examination and may be some tests. It would be prudent to see your doctor and discuss if you may be depressed. Counter-intuitive as it may seem, exercise may help. Start with low intensity exercise such as walking and gradually increase the intensity as tolerated. Drink more water. Wish you good health!