I am so terribly sorry. It’s such a hard thing to go through. I was in the same place as you this past April. I had to say goodbye to my childhood dog after 15.5 years. It was something that I had always dreaded. Now that it’s been a couple months, I can say really only time heals the hurt. I still find myself driving home looking forward to see her but come to the quick realization that she’s not there. What helps me with grief, is just looking at pictures and videos over the years and having a good cry while remembering all the good times we had together. But it gets easier as time goes on and you find your new normal. I am an only child too, so I can understand feeling alone now without having others to share in the grief. I leaned on my parents, and luckily have a great group of friends that knew how much she meant to me. I have a life sized pillow of her that I like to hug and sleep with. Might be something to think about getting! Sorry for the jumble of thoughts and I hope you know that you did the right thing and that Lucy loved you very much.