There are many reasons for headaches. I used to have frequent headaches. I went to a chiropractor to get checked out - and found out my neck was curving forward vs curving back. That was my main headache source. Having my neck with the wrong curve was putting too much pressure on the brain stem triggering the headaches. After getting treatment for a few months, the headaches mostly disappeared.
Then I started noticing other types of headaches. Caffeine withdrawal headaches can occur if you drink too much caffeinated beverages without sufficient water to keep yourself hydrated - sodas, coffee, teas...even headache medicines. If you are taking OTC medication for your headaches, check the ingredients. I had a friend who was taking Tylenol for his chronic headaches - he took the pill, the headache went away, but then came back a few hours later. Turns out this Tylenol product's main ingredient was caffeine, so when the drug wore off, he started getting a caffeine headache, then took more pills. It was a vicious cycle.
Diet can contribute to it - sometimes certain foods can trigger headaches. May want to try tracking if there is any correlation there. My dad would get migraines if he ate dark chocolate. Some enzymes in the dark chocolate triggered the reaction.
Dehydration causes headaches. Are you getting sufficient water?
I get tension headaches - I feel it start in my shoulders and neck, then it runs up into my head if I don't do some stretching and relaxation to relieve the tension source. I also found with my increase in activity levels, I didn't have enough magnesium intake which caused chronic muscle spasms which also contributed to the headaches. Now I take some quality magnesium supplements and those spasms almost never return.
Not sure if any of these relate to your situation. Hopefully if you haven't thought to check for any of these, it'll give you more things to investigate.