I'm fresh out of college and recently started my first full-time job as a software programmer. I started to get some wrist pain, which is somewhat normal (though not good, obviously), so I'm taking steps to avoid that. The main issue is that I'm very tall--nearly 6'9" (2.08m)--so my arms come down to the mouse/keyboard at an angle. I purchased a gel wrist rest for my keyboard to force myself to have the correct typing angle and I also purchased a vertical mouse, but I don't think the latter is working as intended because the required angle puts all of the pressure on my pisiform (?) bone and this is very uncomfortable. I tried sliding the keyboard wrist rest over just to test if a wrist rest would alleviate the problem, but there's so much pressure on that point that even the wrist rest didn't help much.
For some additional information in case it's useful: I do fit underneath the desk, but if I sit properly with my knees forming a 90° angle then there's about a 1/4" distance between my leg and the bottom of the desk. Tight fit (though not uncomfortably so).
(This next part is more additional information, I'm not specifically looking for help with it [though you can answer if you want], I just want to provide all of the information that I can.) As I've been using it this morning, I've been trying to figure out how to correctly hold the mouse, and I can't actually find any information online for the correct way to actually hold a vertical mouse. I keep getting hand cramps from holding it, which would indicate to me that I'm holding it too tightly, but what do I know?
How can I adjust my workstation/desk/chair so that everything is ergonomically correct for my wrists?