We are a few weeks ahead of you here in Australia on the panic buying and toilet paper is one of the few things we actually produce here.
But it's still impossible to get in most places a few weeks after the panic buying first happened. People seem to buy it immediately on reflex, and people who didn't panic buy are beginning to panic search for it.
One factor is that toilet paper is a bulky item, which makes the logistics of shipping and storage tricky. But still! I'm very surprised at how fragile this (fairly simple) supply chain has proven.