Well, it seems to me that you first need to determine if your feet have grown or swelled. The big difference is that, with proper care, the swelling will eventually go away but genuine growth will not.
However, yer never going to find out while wearing heels. The only real answer is to set the heels aside and stay off your feet as much as possible for a week or two. If the swelling starts to go away you'll know that yer feet were protesting too much abuse
and you'll simply have to restrict your heel wearing to perhaps an hour or two at a time. If your feet have actually grown, then you'll have to make the appropriate adjustment when you buy shoes.