First cold - any tips?

My 7 month old has his first cold. It started last Tuesday night and I thought we were over the worst of it, but he is just so snotty and miserable. I have tried Calpol, the snot sucker, the Calpol vapour plug in things and a bath filled using the shower to make lots of steam. Nothing seems to be helping and breastfeeding is just so hard for him as he can't breathe. He will not sit still for the Calpol and the snot sucker. Does anyone have any words of wisdom?! It makes me sad that I can't help him.