By looking at the facts. Right now you missed them and it hurts a lot so emotions are easy to get in the way of you seeing that it was the right decision. :hugs
I don't think there's anything to do, necessarily. If you feel that you made the right choice in giving them up, who cares what other people think? They can judge you all they want but they're not in your shoes. Most times, an animal sanctuary is a great place for animals. I'm sure your...