Ive been feeling nauseous for 6 months and ive taken several blood tests which came back perfectly fine. whats wrong with me?

May be nothing: 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.