Freedom-
I am also quite tall (almost six foot) and have a coworker that is six two. I don't struggle with constant pain, but sitting especially can upset my back because I don't sit correctly.
I got a FIT disk for both my car and my desk at work (they use them for balance to stand on at gyms). Neither cost me more than 25 dollars, but they are worth their weight in gold. I realize you might have a lot more to your pain, but this was something simple that at least prevented problems for me. One of my body workers suggested it.