You have nothing to feel sad about. You tried your best and sometimes adoptions or fostering just don't work out with the other family members. This will be a win-win situation. You and your furbabies will be happier and less stressed and Oliver will find a loving home where he can be the head of the household. You are a wonderful Mommy should not be feeling any guilt at all. As T & P says give him one last hug from all of us and I do hope you will be able to track his progress.