I’m so sorry! Euthanasia is never easy. My first chameleon passed away at the vet before we could decide on it. It tears me up that he was in pain. Thankfully, but also sadly, my second one was euthanized. They passed away within a month of each other, which sent me into a deep depressive state, so I know how you’re feeling. It’s not easy to get past it, but you do get through it. Just try to remember the good times, and reach out to your support system, which includes everyone on here, if you need/want to. Losing a pet is always hard but especially so when you have to decide whether they live or die. You did the correct thing, which I’m sure it doesn’t feel like that right now, but you’ll see it with time. Again, I’m terribly sorry, let me know if I can do anything to help!