I Can't Get Past This Guilt

I put my dog, Tank to sleep Wednesday night. I agonized over whether to do this and made the decision to follow through.

He was a 16 year old yellow lab mix. I rescued him. In the past few years he has had Arthritis in his back legs. I have had him on rymadil for about a year now. it seems to have helped....somedays. I had to carry him up and down the porch stairs. For the last 2 months he has been having bowel movements while he was sleeping and would actually just lay in it not knowing that he even went. I was constantly cleaning it up. This last 4 days he had diarehha.

On Wedneday me and my husband made that dreaded trip to the vets. he sat on my lap with his head out the window. My 1st problem with guilt comes from being a coward and running out of the room right before they did it. How could I leave him like that? All I can see is his big brown eyes staring at me. My husband DID stay so he wasn't alone. I can't get past it. The 2nd is did i do the right thing? Everyone has said "Yes" but in my heart I feel I should have let him stay here longer. One thing that is kind of helping me is that my vet told me he had a gentleman make 3 appointments to have his dog put down and canceled all 3. The last day he canceled his dog (who had bad Arthritis like me Tank) walked out in the yard and fell in the pond. He drowned. Now he has the guilt of not doing it sooner. Hope that helps others. I can't stop crying and i haven't left the house in 3 days. I just can't focus on even driving. This is the worst pain i have ever felt in my life.