Cough suppressants are not a good idea if he is congested. If he is coughing up phlegm he NEEDS to get that out. Supressing the cough can lead to pnuemonia because the fluid stays in the lungs. This actually happened to me as a child - my parents gave me Triaminic hoping it would stop the coughing and let me sleep.. and I ended up with pneumonia. So lesson learned - only use cough suppressants when its a dry cough.
Have you done the good old fashioned nasal saline solution and a bulb to suck out the mucous? It's not pretty but it really works. Nasal saline is cheap and the bulb syringe is a pretty standard baby item. Just put a few drops in his nose, squeeze the air out of the bulb and then put it in his nostril and quickly release. It basically "blows" the childs nose... just in reverse.. by sucking out all that gunk.
When you say "Vicks baby" -- do you mean the Vapo Rub? Thats a winner at my house. I put it right under my kids nose and even on the end of his nose. It helps protect the skin from getting raw from the drainage and rubbing it with a tissue too.
You said you have a humidifier -- they have menthol you can add to humidifiers to help when they have a cold. You could ask a pharmacist about this.
There aren't many medicines that are "ok" for 2 and under over the counter. Last I checked Dr. Sears website still had what dosages to use of the childrens medicines. Please, please be so careful whatever you give him - the reason all of the infant cold medicines were pulled were from people overdosing their kids. Medicine, even stuff over the counter, is only "safe" if used in correct doses. I would look for a decongestant for kids and possibly an antihistamine. Sometimes our sinuses get inflamed and irritated and it becomes a cycle - drainage because its inflamed, it stays inflamed from all the drainage.
Sorry your baby is sick. Hope he gets better quickly.