Markus, there's nothing silly about love! I'm sorry for your loss. Your feelings of guilt are natural, but please keep in mind you did the best you could at that moment. You did exceptionally well by even making the decision to ease Minki's pain and suffering. Not everyone can do that.

I heard this recently, and maybe it can help you:

"Don't cry because it's over, smile because it happened."

You have many wonderful memories of Minki! Smile because you shared your life with a wonderful friend.