Why won't Flash update/uninstall?

I use Mozilla Firefox on Windows 8 and for the past few weeks I've been having a lot of issues with Adobe Shockwave Flash player. Youtube, Pandora Radio, and anything that uses Flash will crash my entire browser within seconds of being opened. I attempted to update Flash, but the update application didn't even open and remained unresponsive for more than 3 consecutive tries, with total CPU reboots in between. The one time I got it to open, it gave the message "connecting" for over an hour. Someone said that I may need to uninstall the version of Flash that's already on my computer, so I downloaded the uninstaller and ran as an administrator, but it also didn't open even after restarting the computer, disabling the Flash add-on in my browser, and closing down all applications/browsers running in the background that use Flash. I've got nothing... What do I do?