OP, your post title is very specific. Did your doctor tell you this was what it was? Without getting a more complete history and doing an exam, your symptoms sound more like vertigo, the feeling you get when you jump off a merry-go-round and the world swirls. Is that a possibility?
I’m asking because vertigo has a completely different set of causes than orthostatic hypotension.
In the interest of being mindful of Occam’s Razor, let’s just forget about your rash and your skin cream for now.