Beta blockers are only real helpful if you have significant tachy rates. It's doesn't sound like that's much of a problem for you either.

If your BP corrects itself that fast, then does your light-headedness correct that fast too?

Your BP in the arm may not be the same as in the brain, but it is relative to symptoms...if the arm BP is low, then so is the brain and most people are symptomatic when the arm BP drops to a certain level. It doesn't really matter what your BP is (arm or brain). Some people are symptomatic at 95/65. I have had this so many years that I can function with systolics into the 80's and don't get real lightheaded until the low 80's or 70's. It also depends on how fast the drop is. A 30-40 point drop in 1-3 minutes will usually cause symptoms (regardless of BP numbers) faster and more profound then 40 point drop over 15 minutes (even if it goes into the 80's).

Florinef is a corticosteroid and helps to retain volume and salt. Have you tried a simple high salt diet yet?

It sounds like you have significant lightheadedness...more so then your BP dictates (if it corrects itself that quickly). What did your tilt table test show?

Some simple suggestions would be to avoid caffeine (all), increase fluid intake, and increase salt intake. If you still have problems, then try a low dose (no more then .05mg) of florinef.