Sacred Haven of Debauchery

That's just your internet connection.

It's not the internet; the slowdown isn't due to loading, but the program itself. Sometimes it just freezes, and that's it. After that, nothing helps except restarting the computer.

Added 1 minute ago
Chrome works fine for me and still does. It's smooth and responsive.
But Firefox still has some features that I like, which is why I'll keep using it instead of Chrome.