Am I over-reacting or being selfish?

Honestly? I think you've been way too generous, and your fiance has been taking advantage of your good nature. Fair enough he had to fly home for a family emergency, but allowing you to pay for more than half the wedding is a bit much. I don't think you are over reacting or being selfish, i think you have been giving a lot and getting very little back in return. Give and take is necessary as it keeps things balanced.