Also to consider: You are still taking that lisinopril for blood pressure? This drug crosses the blood brain barrier and goes into the brain. It is good for this because it can help with inflammation it is thought.

However, this increases side effects, especially dizziness. When I received a generic for this from INDIA...I was so dizzy I couldn't walk.
I had to go to another pharmacy to get my old brand of generic back!
I don't know what was wrong with the INDIA one unless they were made wrong and too much drug was in them for the dose.

Now that you have lost weight and are doing a good job with your diabetes, you might need a dose adjustment?
Dizziness that occurs when you bend over and then stand up may be orthostatic hypotension.

Sometimes my lisinopril makes me dizzy, so I use that sign to take my BP and typically I find it low. So I do half dose for a short time while monitoring it.

Another possibility is that you are developing an autonomic neuropathy --I hope NOT. But BP changes with position also happen with that.

You can get a virus in the inner ear which can cause vertigo. This vertigo does not go away once you change position. Typically it is self limiting.