Sinusitis..

In surfing I haven’t really had any problems with muscles or my actual body (other than injuries ofc), but I don’t get off the hook that easy as I get really bad sinus problems after I surf in the colder months. Usually headache ear ache and tooth ache where the sinus swells up, but I’m used to it and it normally comes after a run of swell when it’s flat so I never think too hard about it, just get on with it, however after surfing my brains out earlier this week I got it so bad I had a constant heavy thumping pain in my head and my forehead was super sensitive to the touch. After a few days of living off painkillers and on almost no sleep, I’ve started antibiotics which is starting to help but is still feeling pretty bad. I don’t particularly want this to happen again, so does anyone here have any tips n tricks for helping out sinuses and preventing sinusitis? I saw on a Nathan Florence video how he clears his sinuses and although it works and I always do it after a surf I can still get inflammation after surfing, although less frequently than before! Thanks in advance 
