I would bet the direct light on your face from the monitor and the lamp contributing to your headaches. That is a very high amount of strain on your eyes. Please turn your monitor brightness down, and other people are saying you don’t need to have it directly at you for 8 hours. That seems very excessive, and you even said it’s not enough, so you may want to just look at alternatives and curbing the headaches. Have you considered going to therapy or seeing a psychiatrist about this?
Disclaimer: none of this is medical advice and you should seek profession opinion