I Made An Awful Mistake

we had a wild bunny named Mr. Rosie Cottontail, for close to four years. When he was a tiny baby his nest was destroyed by a weed eater at my husbands work, and he was the only survivor. Although wild animals should not be kept as pets, we consulted with the wildlife preserve and due to his contact though bottle feeding and his untimidness towards people, and constuction of commerial business on his home land, we did not rerelease him into the wild. We never held him, because he made it very clear he didnt want to be touched, but he let us scratch his nose and recently under his chin. He would hop up on us and say hi, and wasnt afraid of us. He was fine as long as he initiated the contact. Recently we adopted another bunny a domestic. We took her to the vet for her first exam, and upon advice of the vet, i agreed to bring our Mr. Cottontail for his first exam, to make sure he was the correct weight and everything was going fine. We had been feeding him designer rabbit food, with nuts and corn, and recently I learned these foods are not good for rabbits. I wanted to make sure that he was okay. I was concerned about his weight. Now i realize he had probably just lost his winter coat.
My husband thought the vet visit was a bad idea and that the stress would be too much for him. But i went ahead with it. He had been on plenty of car rides and we have traveled with him in the past. I warned the vet that he wasnt handled and that I feared he would have a heart attack. But they assured me he would be okay, that they were experienced with wild rabbits. I brought him in, they were after some effort able to catch him , wrap him, check his ears, look at his behind and weigh him. They put him back in his carry box, and I left. I didnt open the box in the car in fear he would leap out. I headed directly home, went over to his pen, and opened the box, he was dead in the box. I feel so guilty that i didnt trust my instict. I feel guilty that I caused him death and took him away from the rest of my family. Its hard for me to talk to my husband about this, because i feel so guilty, .. I am not sure how to cope. If i had only not taken him to the doctors today. Before we left the vet told me how healthy he looked. Bunnies are supposed to have a life span of 7 years. I feel like I took those years away. I meant to do the right thing, and i made an awful mistake. Maybe sometimes you can cause harm by doing too much. ...