Hiya. All my cats had a terrible cold last year, the youngest (and tiniest) got very poorly.
1) keep the dropper water thing going, no matter how he squirms.
2) make sure the nose is free from any snot build up. Warm water on a soft cloth is ideal. Pick it if you have to! If he is super bunged up, nasal drops from the chemist for babies helped for my lot (just saline water)
3) same for eyes, bathe them in warm water on soft cotton pads/ very soft cloth. will help him feel less yucky.
3) LOTS of smelly food! try tuna in spring water. (that way you can get a bit more moisture in him), warm it up if need be.
4) hottie under a nice fluffy blanket.
5) peace and quiet.