I wish I had an answer that would satisfy you but I don't. I will say this, though: one of my cats is now close to 20 years old and she was sedated at age 18 for something rather minor at that time and I was nervous about it. Yes, we always worry when we need to have our furkids sedated, especially when they're older, but it's sometimes necessary. You did what you felt you had to do for the health and welfare of your cat. Cats normally wake up more quickly from sedation rather than from anesthesia. You had 7 more months w/your cat that you wouldn't have had otherwise. Try not to feel guilty, although I do understand. I still carry guilt about other things where my cats are concerned because hindsight is always 20/20. You did your best for your cat and that's all that any of us can do. Your kitty is resting at the Rainbow Bridge now and then he'll romp and play like a kitten again. Until then, RIP, little one and peace to you, TommyCat.