When it's every single day and it feels like no one's allowed to have fun or be happy or cheer people on without this person needing to redirect, I just run out of empathy.
If a game environment gives the impression that a player's value is measured by how many scenes they run for others, then it is easy to feel unvalued when you cannot or you do not do the same.
"We still accept you" and "don't feel like you have to run a scene" are platitudes that do not address the underlying problem: that the player has the impression that their value to others is measured by how much they can give them. And when people are constantly heaping praise on those who do give a lot of their time and energy, it is easy for anyone -- this is especially true in our community, I think -- to equate giving with value. But the issue is the heaping of praise; it is in the lack of other measurables that others may seek to validate themselves among their peers. Maybe instead of saying "we accept you," you could point out to the contributions that the player brought to the scene itself or the game as a whole.
That said, and I say this an awful lot because it is self-affirming and unbelievably true: you are worth more than what you can give to other people.