Zeus, God Bless you for what you provide to these rescue animals and condolences on your loss.
My wife and I are both country folk who also connect with animals more than humans. We live on a farm and have had rescue cows, horses, donkeys, chickens, ducks, and pigeons.
Our farm also has an operating dog boarding kennel and training facility (I am a former military K9 handler), and we often foster puppies for the local rescues. It is very hard not to get attached and keep them all. Sometimes, even though I am delighted when a rescue / foster gets adopted by a wonderful and loving individual and especially family, I can also barely make it through saying good bye and watching them drive off.
Over the course of my life I have been witness to many dogs and cat's a few horses being euthanized and it is a most lonely experience and desolate feeling. I just wanted to encourage you through your grief process and to offer you support as you adjust and get ready to do it all over again. You have indeed found a great purpose and anyone who knows and understands animals knows how much it means to them to be touched by a gentle hand, to hear a compassionate and kind tone of voice, and to be given a place of comfort in a loving and safe home while no longer worrying about shelter from the elements or surviving predators or wondering when their belly might be full and satisfied again.
Most importantly, you know, but not all understand, that when an animal that has been lost and alone is held close and feels love and protection, that the innocent and pure affection and appreciation it provides in return is one of the most authentic and genuine things we can experience. May your many future rescues live full and quality lives. Again, God Bless You!