I am so sorry, from the bottom of my heart. You have to tell yourself that these two last, bad days were preceded by hundreds of good ones. He left the world a very loved little horse, and that's the best any of us can do for our animals.
I'm sorry. Not much else to say. I know how you feel (as I'm sure do most who have loved an animal and lost it)and all I can offer is that in time it will hurt less. Be extra kind to each other for a while, you need some TLC during this sad time.
I don't think there is anything I can say beyond how deeply sorry I am to hear this news. Anyone that has been on here for any length of time knows how much he was loved and cared for, such a hard decision that you had to make......