It can be so confusing can't it! What you are describing does sound quite normal for that age. It often seems like they couldn't possibly get enough but often it is surprising how much they drink in a short time.

If he is having at least 5 heavily wet nappies in 24 hours, that's a really good sign that he is getting enough. And if he is getting enough, then he will be providing your nipples with enough stimulation to make the amount of milk he needs.

So it all sounds good to me hun.