If your sinus infection is in the upper sinuses, it will block your olfactories. All the stuff you tried often doesn't work, here's why
http://www.medhelp.org/user_journals/show/2322
The Flip-Turn Sinus Flush is mildly risky, because you have to bend over to do it, preferably in a shower, but you can also do it outside on soft ground, or you can kneel down and lean over a bathtub, or perhaps a plastic basin or tub, with the shower running for steam.
You should see an ENT first, make sure you don't have polyps or something else causing a physical blockage.