Coping With Canine Distemper

My husband and I just got married in February and for years we have dreamed of rescuing a dog. We recently moved to New Mexico for my husbands job and I was bored and lonely. I found a non-profit animal rescue place that rescues dogs from a kill shelter in our town. Thats when it hit me, I saw his picture and knew it was my dog. He was a 1 and a half year old pure bred Golden Retriever and I just couldnt understand how someone would leave him tied to a kill shelter. Not even the shelter could kill him, on his last day they called the non-profit organization to rescue him…and thats how we got him.
He was so healthy just a little skinny from being in the shelter when we saw him first. Then when we picked him up 4 days later, the foster mom said he started getting crusty eyes. We took him home and he was a little lethargic but a GREAT dog nontheless. I took him to the vet a few days later because his eyes were so bad, and they told me he had para-influenza and that he needed to be on 2 antibiotics twice a day as well as saline for his eyes. After that he was GREAT! He needed to be on his antibiotics for 2 weeks and come in for a follow up visit for his “all clear.” But unfortunately things took a turn for the worst.
He was doing great, no more eye discharge nothing. Then 2 days before his all-clear hospital check up he started acting funny. He drank his entire bowl of water and walked him circles wimpering, as if to say “HELP ME” then it happened, a Grand Mal seizure. He fell to the ground seizing for about 2 minutes, no breathing nothing. He finally came too and was soooo very out of it and didnt act like the same dog. The vet said to just keep an eye on him and he should come out of it. Then 12 hours later, another seizure this time longer…and this time he was never the same dog again. We rushed him to the emergency vet who prescribed him valium and anti seizure meds. He didnt have another seizure for 24 hours. Except, he wasnt the same dog, he walked in circles fell over all the time and just layed there, we had to keep him in the kennel most of the time on his last days to keep him from hurting himself. The doctors were optimistic if he didnt have any more seizures for 4 days he would come out of it. Then BOOM just like before more chewing gum fits (seizures that are smaller) this time 4 or 5 in a row. I called the vet and brought him in, and before I knew it, we had to put him to sleep. I as well as my husband are completely devastated. I think of him 24 hours a day and how much he suffered his last few days and how very guilty i feel for having to put him down and keeping him in his kennel so he wouldnt keep hurting himself by running into walls. I have read other stories on here, and it has helped a little, but I am really really heartbroken. He was my baby and EVERYONE in the entire neighborhood loved him. I just keep picturing him on that table limp with a needle in his arm and it breaks my heart. But in the end of his life he didnt know where he was, who he was and who we were so i know we did what we had to to. but i still feel guilty and empty…