There's a light at the end of the tunnel. It's likely whatever energy source for the simulation would be disrupted by some catastrophic event. Even without sentient intervention, over tens of millions of years you've got starvation of some resource -- even if it's something like fusion or the raw resources needed to build and maintain "renewable" energy. Over hundreds of millions or billions of years you've got asteroid impacts and cosmic events, eventually ending with the heat death of the universe. Not so bad after all, just tough it out soldier.

That's not really much of a consolation.