The good news...
Not only is a few billion years time enough for humans to either get off the planet or re-boot the sun, it's even time enough for humans to go extinct and some other species to become smart enough to do that. Several species, come to that.
I have a fun book called "The Future is Wild," that was also a TV show, describing the next 200 million years if humans aren't in the picture. They have a website, with a lot of links and pictures. 200 million years from now mammals are long gone, but a land-dwelling descendant of the squid is swinging through the trees and taking its first long look at the stars. Life goes on.
The negative attitudes about humanity are something that you are being told, not something that is objectively true.