I'm so sorry for your loss...
You have my deepest sympathies.
I know how difficult it is to reach that decision, but in the end you did the right thing. I'm sure your Kyle knows how much he was loved and cared for while with you.
As time goes by, the pain from not having your budgie boy will lessen and you will be able to remember fondly all the good times you had with him, Kyle will always live on in your heart.
Rest in peace, sweet Kyle. You were much loved and will be missed.