Adoption decision

I was accepted to adopt a 6 month old pup from a rescue. My old dog had to be put down 3 weeks ago. Ever since I interviewed for this dog, I can't sleep, and I'm stressed I'm making a mistake. During the day, I'm excited to welcome a new fluffball into our family, and I'm so excited to meet her. This dog Is the same breed and coloring as my old dog, but slightly bigger. Yes, I have a type, but small rescue poodles tend to be white. She is 14 years younger than my old dog, and will have a different energy. In the past, I've always waited about a year before getting a new dog. My remaining dog, a German shepherd, seems OK being an only dog, but I really miss having a small snuggly dog. I'm not going to be any less sad about my old dog's passing a year from now. Since I'm in my 60s, and retired, this will be my last dog. My motto is, if it isn't a heck yeah, its a heck no. Do my sleepless anxiety filled nights mean i'm making a mistake?