My cat is really congested![can't even miow]?

you need to check if she has a fever you got get a thermometer she could have a upper respiratory infection URI if her temp is over 102.0 she has a fever and needs to go to the emergency clinic. If she doesn't have a fever then what you can do in the mean time while your waiting to go to the vet is get kitty and take her into the bathroom close the windows and door and turn on the shower all the way to hot and let the bathroom fill up with steam let it run till its like a sauna an let kitty steam for about half an hour this will open up the air way help kitty breathe easier. I hope kitty feels better:):):)