I am 30 and often wake up with a bad headache. I think it's related to my sinuses as I am always blocked up in the morning. Is there anything I can do besides medication?
I think the first thing you need to do is to have your condition properly diagnosed. You may be right, it could be sinusitis, but there are issues there that need to be teased out. Is this due to infection or is it associated with nasal allergy? Could your symptoms be related to your work environment? Maybe you have nasal polyps. I sympathise with your reluctance to go down the route of taking medication but before that becomes an issue you need to be diagnosed. Proper diagnosis before treatment is the only logical way to proceed here.