Subpage & 404 missing mysteriously…

I just noticed yesterday that my main page is showing up but none of my subpages show when clicked on. It’s like it’s lost the link to my template page or something. Can anyone help? I have re-installed wordpress and nothing. I have made no changes to this website. I can’t figure it out. I tried contacting my server, but they just don’t get the problem and keep asking me to re-upload the folder that has the file in it. I keep trying to get them to understand that this is done via php and I have no local folder that corresponds to the subpages…

my domain is epic4life.com