Welcome to the forum.
Sounds as if you have light sensitivity. Sun and flourencsent lights are big triggers for a lot of people.
Which may put you in the migraine family of headaches. If your doctor didn't give you much information. I would ask for a referral to a neurologist. Or find one on your own depending on your insurance. You want to find one that deals with migraine pain.
The causative factor for why the started is rarely found, but if the pain is daily, a person can be put on maintenance meds to reduce or prevent the headaches. https://www.mayoclinic.org/diseases-conditions/migraine-headache/symptoms-causes/syc-20360201
Peace and strength