If you have a lot of chest congestion, there's a diabetic tussin that you can get OTC. I can't take any tussins because I'm allergic to guaifenisin, so I'm SOL!
My dad says the stuff tastes disgusting, but it does work well... No one in my house has tried it (my hubby is also diabetic), so I can't tell you if it works or not...
Other than that, steam showers are good. I also like the new "plug in" type of vaporizors that are out there. Mostly they're made for children's rooms, but they work for adults too. I believe they are made by the Sudafed people, but don't quote me on that! LOL
Drink lots of water and test your bg often!