Ha!! I hear ya!! I am just now starting to think there may be hope for MY energy level!!
Coby is 7 1/2 months old and was neutered about a month ago. I don't know if it's one or the other or the combination of both, but he is STARTING to slow down a little (with emphasis on the STARTING part!). They are, and most will always be, a high energy dog. I also have a Shi Tzu, and they are low to medium energy dogs. There's a big difference between them. But I'd say around 6 to 7 months, you'll at least start to see a bit more down time. Hang in there until then!!