I am so very very sorry for your loss of your beloved Beau. You made the only decision you could under absolutely heartbreaking circumstances, and if - God forbid - the same thing happened to my Callie, I would have done exactly what you did. You let him go rather than watch him suffer any more, and the photo you attached shows how much he loved, appreciated and trusted you. He is now in a place where his spirit is free from pain and his body is healthy again. And most important of all, his last hours were spent in the company of the person who loved him enough to be able to let him go peacefully, without pain and in a familiar environment. The most important thing now is for you to take as much time as you need to grieve. Surround yourself with people who care about you and who you can trust to support you. Everyone grieves differently, but the pain will grow less over time. Not today, not tomorrow, maybe not even next year, but eventually, the Beau-sized hole in your heart will begin to ache a little less, and the pain and guilt you are now feeling will start to fade, to be replaced by all the good memories you shared. Also, your boy shared a name with a Quarter Horse I used to ride. He crossed over last March, but I bet he's checking out the new arrival now. Beau the horse was such a sweet, friendly boy that I can't imagine him NOT saying hi to his brother-in-name.
Callie - my dog daughter
Tigger & Katrina - my angel kitties