Well, I actually have been WAITING until I feel pressure or pain, then I equalize. Sounds like we may have come up with my real problem. OK...So, in addition to all those other great ideas, I need to be equalizing every couple feet REGARDLESS of whether there's pressure or pain...OK...Thanks to all who recognized this shortcoming!
This is the problem 99%. If you're waiting to equalize, especially to the point of pain, you causing minor barotrauma to your ears and they are responding with inflammation causing your congestion. Try the early and often and see what happens. Equalize with every exhalation on your descent and you might not ever have another issue.
Of course, if things persist, see a diving Doc.
Good luck with this.