Fedora is a Desktop OS, not a server OS. Proxmox is ok, but overkill for your needs.
Ubuntu server is what you’re looking for. 12 years of security updates, officially supported livepatch (so no reboots after even kernel updates), and official support.
Hire a professional. This is not a safe thing to do yourself. Any server needs to be professionally secured.
Nope replaced it with nextcloud years ago. Install Ubuntu LTS and then:
sudo snap install nextcloud-server
It’s installed!
This is undiagnosed mental illness. Please get a mental health assessment (any hospital can probably do it, just call around).
It gets better. When I did this I was diagnosed with PTSD and anxiety. They put me on meds that immediately solved 50% of my worst symptoms. Overnight.
It was magical and my life has only continued to improve ever since