It will drop off but that's the idea

It's a gradual process of replacing a milk diet with food.
At that age they are much more efficient at feeding so don't take as long. But it is strange when you are use to spending a great deal of your day sitting on the couch feeding!
The cold will probably be having an impact as well though, hard to feed went you can't breathe through your nose! Don't worry about your supply, it's all supply and demand so you body will produce as much as he wants.
My boy was having four feeds a day from about 6mths, 7am, 11am, 3pm and 6.30pm. Now at 10mths he has dropped the 3pm feed and has a snack and water instead.
If you are really worried about your supply you could try tiger milk to give it a boost, worked for me in the early days.
Tigers Milk:
2L milk
2 Tbs milo
2 Tbs brewers yeast
2 bananas
2 eggs
Honey to taste
Blend together and drink 3-4 large glasses a day