Don't add Vitamin D without a blood test first. It is one of the few vitamins that your body can store and it can build up to be too much if you don't know for sure that you are low on it. But the test is worth it as it really helps to correct a deficiency.

I don't think you are on that much medication. It often takes several meds to get stabilized. Sometimes when you've been stable for a while you can start to come down on things to find the least necessary meds.