Thanks for posting your query.
There are 15-20 types of headache have been defined and exact diagnosis has been done only on history basis.
Do you have pulsating type of headache?
Do you have running nose and tears from eyes during headache episodes?
As mentioned by you, Your headache is excaerbating after sunexposure, this is very typical and specific for migraine
You should consult with neurologist/ physician and should take anti0migraien medicine, both for pain relief and prophylaxis.
Dr. Mayank Bhargava