This is because for some annoying reason, Garry's Mod has suddenly stopped working. I have no idea why, I haven't installed any mods lately, or anything at all. When I open it, I just get a black screen, which has to be terminated using Task Manager. This really sucks because I was really amped to make another Psymonic Disasterpiece episode.
However, I am currently working on restoring my Windows XP installation, as I have installed one of my old hard drives which I decommissioned awhile ago, which I can use to install XP on. But until then, there's nothing Garry's Mod related that I can do.