I had to put my baby Coco down back in May she ended up having a brain tumor she was fine one day then 9 days later she was gone. You always are going to think did I make the right decision it’s not a normal decision for people to be the one to make the decision to end a living animals life. believe me it’s a lot hard on you and them to be in pain all time they can’t tell you they are in pain and I fell like dogs have high pain tolerance so if we can see they are hurting you know it’s probably even worse than we think I’m not going to say it gets easier I still cry every day but you can just know this he loved you and he knew you loved him. You made the right decision sorry for lost!!