Headaches are weird because there are various types of headaches. Some come from strain or stress, others are related to illness and or pre-existing medical conditions. It largely depends on yourself. Personally I believe in your case it is the cause of frequent use of the computer. I too use the computer a lot for both work and hobbies, and if I don't take a break, it can end up doing me beans in. So, best idea for you is to limit your exposure not only computers but TV and phone, etc. Not only is the display disruptive due to the lighting. It can lead to problems with eyesight, such as short sighted-ness. So take breaks. Also turn down the brightness of the screen, a lot of people have their screen glare out at them when it's simply not required.
In short: Eye strain, take breaks. Eat kitkats.