They're definitely appropriate responses. First, let's distinguish two different things:

1. Being happy
2. Engaging in desired leisure activities

Since it's very difficult for, say, depressed people to fix the world's problems, I think being happy is actually a step towards solving them, if it gives you the energy and motivation you need. I see happiness as an instrumental goal, not a terminal one. In fact, I suspect you'd be happier when you stop procrastinating and do something that works towards what you really care about.

As far as the second point, I know Eliezer has thought about this question, and has said before that if his help wasn't urgently needed to save the world, he would do other things, like be a science-fiction writer. Depends on how much of a duty you feel you owe the world. For instance, suppose you walk past a kid drowning, and you could save the kid with a few minutes of effort. Do you have a duty to save the kid, or is it just a good thing to do, but not required?

These things keep me up at night, sometimes.

I think it's worth noting that not sleeping well and feeling bad doesn't help towards either saving the world or reaching your own goals.