I cannot think of an obvious relationship between hyperacidity and vertigo. You have had a number of tests done which have all been normal; though that is reassuring, it doesn't answer why you are experiencing the symptoms that you are. A good way to proceed might be to find a good general medical doctor, who will take some time over your case. He/she should take a detailed account of your symptoms, perform a full examination, and review the tests you have had till date. They will then be in a good position to suggest the appropriate way to proceed. They will also take a look at the medications you have been prescribed and recommend any changes that might be needed. It can be very frustrating suffering from symptoms and not being able to quickly get an answer as to the cause; this is why it is important to find a doctor who will work with you to get to the bottom of it.