Hello Imarni, it's always so upsetting when we read comments like what you've told us because some of us have been in exactly the same position and know how devastating having to do this is just so heartbreaking.
It leaves us with an enormous hole in our heart always wondering whether or not it could have been avoided, that's what we don't know but only wish it didn't need to be done, I only want to offer my commiserations and feel so deeply the pain this has left you with, and I say this because I had to do the same with my 18 year dog, who followed me everywhere I went but she had cancer.
You are right other people may say they are so sorry for your loss but don't appreciate how much we loved our pets and expect us to naturally get on with our lives, it's not that easy because we come home and your dog is not there to come running towards you and expect an enormous pat, showing their utmost love and affection towards you.
It does leave you with a feeling that love is missing, it's not the same as a person who loves you, it's different and only the owner knows what it feels like and no other dog can replace the one you've lost, each has their own personality and small idiosyncrasies that the owner only knows about.
I feel so deeply for you and just so sorry this was to happen to you and you have my absolute sympathy.
Please take care.