I've lost everything and I don't know how to get it back. How can I repair my system all I have is a usb with slax linux. I am freaking out because I had a lot of projects on their that I hadn't pushed to github as well as my configs and rice. Is there any way to repair my system? Can I get a shell from systemd?
Boot to a liveUSB of the distro of your choice, create a chroot to your install, and then run a Pacman update from there.
Googling “Arch rescue chroot” should point you in the right direction. Good luck!