Same! I lost days looking for the most distant galaxies and traveling to them. I always felt the same anxiety of the emptiness thinking why the universe doesn't give us a way to explore it, why I was born so early or in a _lame low tech planet_ (in a lame low tech country) or how incredibly diverse could be the life out there. I remember being fascinated by the sheer number of galaxies and then "wait, this app doesn't even zoom _into_ galaxies", which is another level of infinityness, and that was just overwhelming. Man, I feel depressed now.

If you want to fly around galaxies and feel insignificant, Space Engine is pretty good for that. It's not a true simulation, as most things are procedurally generated unless an addon is installed, but it certainly captures the scale of things.