Nausea since 4 months, gagging starts randomly throughout the day. can't tell what is triggering it. stays 24/7, can't go out. all tests clear, gi test was normal too should i see a psychologist/psychiatrist?

If 'tests' are clear than it is good news that there is no serious organic cause. Try, menthol bits, cardamom, turmeric and similar home remedies and try a vaid or homeopath. If not helpful then it is a good idea to see a psychiatrist

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!

I would definitely consult a mental health professional for this overactive gag reflex which apparently has a psychogenic basis.Anxiety or unpleasant thoughts may be playing a role. Stress management therapy or hypnosis therapy may be effective here.