> Like what's even the point of all this, of life, of us, if in the end nothing matters, everything decays into nothingness.

I don't understand this reasoning. If the universe had a different end state, or if it collapsed in on itself only to erupt again, would that make any difference to the meaning of your life or that of our civilization? Probably not, because things still end.

It seems to me that you'd arrive at this conclusion of meaninglessness in any case. The thing is, while the universe may not care, there are many things we as humans do care about. They have meaning because we give them meaning. Isn't that liberating?