The sinus problems can actually be fairly easily rectified - it is the ears that are the problem.
You can go for what they call FESS - facial endoscopic sinus surgery. It involves burning away excess flesh from the passageways so that when they get inflamed, there is still enough room for the air to get in and out. It can help the ears too by helping mucus drain but from what I have heard it doesn't really. Once the gunk is in the eustachian tubes it is hard to get out.
I too have found that exercise can help - I understand it is because working out causes the body to release adrenalin - this kind of "fight or flight" response helps open up the tubes a bit as the body tries to get more air in. I have been told that decongestant tablets work in a similar way.
Also you can try expectorants - they work in a different way - they thin the mucus instead - normally designed to help chesty coughs etc. but seem to help some people (not me though). Best check, but the CAA seem to be OK with "non drowsy" expectorants.
Drinking lots of water helps a bit - I have read similar things on this site too - it helps thin the mucus.