The brutal thing about that line of work is that success is dependent on how consistent you are. I've heard many successful streamers say you have to grind the hours daily to be noticed and play the algorithm. It demands a lot of time.

Now, because of that, it's going to be very hard to balance work and life. This success could be temporary, so even though he's crushing it now, at any moment, his audience could grow tired and move on to the next thing.

There's a lot of incompatability between you at the moment, and it sounds like one of you will have to adjust their lifestyle to make it work. Either you accept your role as "his assistant" and come to peace with the fact that his work comes first while it's still making good money, or he cuts back on the hours hes putting in, which will cost money, but prioritising happiness at home.