Having a hard time despite making the right decision

I had a neck surgery in 2009 on my spine. My spinal column is more stable now than it was but is still very fragile. My physicians are split. Some want me to have another surgery and the others want me to just be careful with my activities. I have a great deal of anxiety regarding my neck. I'm terrified of being paralyzed. For that reason we asked for a child that was walking and had good motor skills so that he/she could do for him/herself. We were matched with a 23 month old in August and had less than 2 weeks to make our decision due to the foster family wanting him placed before their vacation so he wouldn't have to go into respite. We had one evening visit and one overnight. Then we moved him in 4 days later. After 2 nights I knew I'd made a mistake. I was getting new symptoms of pain and numbness in areas I wasn't used to and my ability to use my fine motors control such as to type was affected. I vowed not to pick him up anymore and we started trying to make changes. I got stools and he started using them to get into his high chair, the bath and his car seat. After a week I was still in bad shape and we asked that he be moved. Another week went by and on moving day I begged them to let me keep him. They agreed and I was thrilled, but by the time I went to bed I was having the scary symptoms again. I woke with a great deal of anxiety and called the original foster mother who has been so kind to me. She agreed to take him for the rest of the weekend and on Monday we told the social workers. They were very understanding. For a week I was fine and felt relief that my symptoms started to subside. Then as soon as I started feeling better I started second guessing myself. Then I started mourning in earnest. We had a vacation planned to the beach and I had been looking forward to playing in the sand with our new little boy. I'm so glad I had sunglasses on to hide my tears. Our little girl who is 8 and has been begging for a little boy since she was 3 was ok because we took a friend for her to play with but when we got back home on friday it his us anew. Everything reminds us of him. She is sad, I am sad. My husband however feels ok with everything and is not even sure he wants to try again. In fact everyone is so accepting of this. Everyone agrees we did the right thing but I feel so horrible. I want people to hate me as much as I do. What we did was horrible and I am so ashamed that I didn't try harder. I keep wondering if there wasn't something else we could have tried. And of course there is the anxiety. I wonder how much of my decision was affected by the anxiety I feel about my neck. What if I had taken anxiety meds. I've never even tried that. And I keep thinking that he wouldn't have been such a handful forever. His 2 year birthday was last week and then this time next year he would be like a different kid. Even 6 months would have made a difference but I have to remember that I couldn't make it through a weekend, let alone 6 months. I am having such a hard time. I want to try again but we must get an older child and I know an older child has different problems. I'm special needs enough by myself so we cannot handle any outbursts that require physical strength to get in control. I hope someone out there has some words for me to help me put this all in perspective. I just don't know how to move on.