Hi nat, poor little one, Eats seemed to have a cold practically every month in his first year and I agree, none of that stuff seems to work! I did everything you did, but also put a bowl of hot water with baby olbas or karvol in, near his cot, as well as some on a tissue near his head. I also used nasal drops which you can get from the chemist, and one of those nasal aspirators (not sure if that's the right name) where you basically suck any erm, snot and gunk out of their nostrils - you don't suck it far enough for it to go into your mouth!
You could also try sitting with her in the bathroom and running a hot bath or put the shower on - obviously best done during the day or just before bed.
Hopefully the antib's will kick in soon hun!
x