My name is Apollo!

Apollo is a blue and tan merle Australian Shepherd.
I adopted him about a month ago from a shelter, and though I cannot continue to care for him, I wanted to place him with a loving owner that is a good fit for him instead of returning him to the shelter.
Apollo is sweet, loves to cuddle, has tons of energy, and may or may not be fully grown (he is 41 pounds now, about 12 months old they think, and may gain another 10 pounds in the next 4 months).
He is incredibly intelligent and loves praise, treats, and food.
He wants to be close to you all the time, as they say, Aussies are velcro dogs.
Now here is where the incompatibility is.
I absolutely adore Apollo. However, he needs a lot of space to run, ideally a home with other dogs around his age, as he loves to play with dogs, and time. I just started a second job that keeps me out of the house and too busy to give him what he needs. Because of this he has begun having behavioral issues, mouthing, nipping, and barking.