Are you sitting ergonomically? It's never too late to fix your wrong sitting postures! 

All the tips here are great, except there is a fatal flaw. The screen and keyboard are not correctly positioned. If someone was to use this set up they would naturally lean their head forward to look down at the screen. Correct positioning of the screen and keyboard: The top of the screen should be at eye level, and it should be tilted up slightly. A separate keyboard should be used as bending the wrist in that position is unnatural and reduces typing efficiency.

your hand should be at least 90 degree to the desk, rise the chair height if needed, use a leg rest. put something under your laptop stand and raise your laptop screen to match your eye level

Wrong hand position at the end

I sit like v2 in 4-4

Reduce your table height

A third party lumbar support just degrades that chair completely. Get a decent chair lol

Does anyone know what chair this is in the video