Smiling inside because my Titan has brought me to tears with his endless energy.. literally cried like a little girl once when I didn't know what else to do for him after HOURS of fetch, running, hiking, you name it. He was EXACTLY like you described.. I mean to the T. He had no stop button what so ever. SO I will explain how I handled it and how miraculously it worked for him. Not that this is the only solution but it's just my experience when I was going through the same issue..
I regulated play time. Sounds simple and silly but I did and still do. All his toys go in a box out of his reach and when I
want to play.. we play.. otherwise he gets a chew like marrow bone, raw hide, or antler. He no longer gets 100% access to his toys. Not even one. None outside, ever. I bring them out when it's play time. I LOVE his energy and it's so great to have when we are working SAR because he can go on FOREVER. But after I get home from work and he's out for a walk and we play.. I just want company, I want a calm dog inside the house that will sit down, chew on his bone and watch TV with me or sit by my feet while I do homework or a report from work.. too much to ask for?? maybe.. but that's what he does now. He is exactly the dog that I want him to be. He's obedient and he still plays all the time but only when I tell him we can. Because remember those are your
toys that you
are letting him play with. Not the other way around. By him bringing toys to you he is dictating when playtime is and saying he is incharge at that moment.. "I don't care what you are doing, I want to play." Is essentially what he is saying.
I will admit.. I felt TERRIBLE taking away his toys.. but I learned that it was for his own good and that I wasn't depriving him of playing.. just making it a more controled environment, which is exactly what a dog needs. But now my house hold is so much more peaceful (as peasceful as it can be with a GSD and Boerboel... lol) but there's no more dropping balls, stuffed, toys, frisbees, etc into my lap when I am doing something. There's no more whining to play with all the toys that are lying around the room.. he just knows.. He will play when mom says he can.. and he will play HARD because mom says he can
I know the feeling and I really hope that helps..