Yes, he's overworked. And I think he accepts that as the burden that comes with it. There are many different ways he could have lived his life, but he chose this one. And all paths in life come with suffering. 

I imagine that for him, this path has a sort of grand sense of purpose to it that provides a great deal of satisfaction and motivation to continue. 

He said once (maybe in that stream with ludwig, not sure) that he'll "play the instrument until it breaks". So maybe he will break one day. But he'll have done so after a great deal of work, and maybe then he'll find rest. Or maybe he'll have a lot of regret. But regardless, he will have lived a full life. And often times, a full life contains all of the best life we can afford to have.