Heart palpitations for the past 3 days. they said i was fine. havent had an oz of caffeine since. they diagnosed me with anxiety but i havent been anxious. they also mentioned my potassium was a little low. could i have heart disease or any problem?

It is not feasible to provide an opinion without additional history, physical examination may be some tests. It would be prudent to see your doctor to see if you may be depressed. Depression is treatable. 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!