This could be inner ear bacterial type stuff as the others have mentioned.
Need more information. Such as digestive symptoms at all?? constipation, foul stool/gas, bloating? It does not seem likely that you would not have ANY digestive symptoms and yet have some some degree of gut flora imbalance.
I am curious, do you have low blood oxygen levels as evidenced by flushing red/dark red/blueish color in hands and feet. Any discoloration of the hands/fingers at the same time as the faint/dizzy/panic spells happen? If so, get back to me, I can help but it's a long story.
Aside from that, dizziness upon rising is associated with weak adrenals/slugish thyroid function.