Hi! I have been through a very similar situation. My son, now almost 3 1/2 got his first cold at 2 mos. and it was downhill from there.
I have done the tubes in his ears, twice actually and that does help with the infections. We have been to an allergist, all of the tests came back negative. (One of the big problems with testing before 5 is that they may or may not react to the allergan.)
His doctors thought it was asthma, so we did nebulizer treatments and Singulair. Then I took him to an ENT, 'round and 'round. I know EXACTLY how you feel.
When all of this first started, my pediatrician told me to just hang on, that it would get better as he got older. I hate to say it, but it has. Now, he has a runny nose and cough occasionially, but NOTHING like it was.
Have you tried the Zyrtec? Or, what I found that works better is Dimetapp. I don't give it to him everyday, or even as directed on the bottle. Usually just once at night calms everything down so he can sleep. Is it better now that it's not cold weather?
Hang in there! I know this is driving you mad!