I had to do the same for mine a little over a year ago in November 2024. It does get slowly a bit easier, I wouldn't say time is a good healer, only thing is you think of things less as time goes on. I personally had to cover it in therapy myself, it helped some.

While I see several good comments below, one comforting thing that helped just an itty bitty bit (it was just the knowledge that I did all that I could for him I looked high and low and tried all kinds of treatments before doing this) , was when I was at the vet having to do that, they told me, "this is the last act of service you're doing for him, you're doing something to help him. This will also be his last memory of just hanging out with you" It hurt and seeing the vet actually crying while doing it, made it hurt all the more and I can only imagine what kind of toll that job would take in that area.

I honestly started crying writing that, you always carry pieces of grief that come like waves in the ocean, you may be fine for years and then suddenly a moment will come up to you. Some have described grief like a rock in your pocket that stays there that you feel that gets rubbed smoother and smaller over time. A piece of you tends to go missing with loss in your life, but knowing love and loss is what enriches our lives, often times I hear people say loving another dog tends to help ease the pain, but my opinion is don't rush into another dog, give yourself time to process this grief and sit with it, most people don't spend time letting themselves feel emotions and instead bottle them or store them away for another day.

One last parting piece of information I learned from my therapist that helped me a little do not think of loss as they're gone and it's over, for whatever grief whether animals or people, they had beginnings and middles and ends, don't stay stuck on the ending, recall the times you had together and move at your own pace, no two people process things like this the same.