My heart hurts with yours even as I smile at the pix you took of Sebastian. What a gift he was in both your life and that of your family and friends.
"He licked my tears and calmed me when my heart was broken. He instigated play when my spirit wanted to do nothing."
Those words resonated with understanding as I read them. My late, beloved Charlie Dog was also that dog and I miss him terribly.
Many hugs to you as you heal from this loss of your sweet Sebastian.
"Not all those who wander are lost."
(J.R.R. Tolkein from Lord of the Rings..."Strider's Poem")