It was pretty shocking when it happened- I was feeding him like I always do, when suddenly he let out a guttural yowl and collapsed, passing out and urinating on the floor. He woke up shortly afterwards and we rushed him to the vet. They said he had problems with his heart and liver, and might have had a seizure, possibly from a brain tumor. After all that, we decided to finally put him down. We stuck with him the whole time, and he quietly passed away. I've never seen a pet getting put down before- we were waiting for at least half an hour, but in the end it took them less than a minute to put Gulliver to sleep.
Thankfully, my whole family and I were able to be there for him this time- I was at work when Anya was put down, which made it hard to come home after that, even harder to bury her afterwards. Though regardless, I feel just as drained mentally and emotionally as I was before. It's going to be hard to get used to life without our cats.
Take care of your pets, folks. They're only there for a part of your life, but you'll be there until the end for them.