I'm so sorry! We lost our beautiful Retriever at 11 years old, over 5 years ago and it's still so hard to remember
We only waited 2 months and got another Retriever mix puppy. She's a great dog too!! It's a huge adjustment getting a puppy after having an older dog, so just make sure you have the energy, crates, toys, etc. I was shocked at the needs of our new puppy, even though we're a dog friendly house.
My great Vet said to make sure not to (negatively) compare the new puppy too much against your dog. Puppies need time to become your new companion.
Also he said they fit in more than enough love to make up for their shorter lives. I found it helpful to find other people online that lost dogs, reading their thoughts. A video I like watching recently is
https://www.youtube.com/watch?v=P2zQbsEGh_Q.
Also the rainbow bridge poem - your baby is running and having fun with all the others at rainbow bridge!!