Our 5 month old is wheezy?

hello, our 5 month old son has had a cold for about a week now and a little cough we have took him to the doc 2 times and they just gave him some antibodis once cause she said he had a little ear infection, and a cold, other than that she said give him dimetap from time to time well he is really congested and we use a humidifer and have been steaming up the bathroom but he is also pretty wheezy, you can hear him when he breethes