I bought joomSEF after reading the reviews on Joomla! I'm not exactly a programming expert, so I went ahead and installed the zip file like every other component...

BAD IDEA! Since then my website's been offline and I can't access the backend! I deleted .htaccess, switched it with a Joomla! unedited alternative, tried the one stated in the documentation here,

www.artio.net/en/joomsef/artio-joomsef-documentation#intro

..and NOTHING. It's been four hours, could someone please just tell me how can I fix this? I don't wanna do a reinstall, and I can't believe I can't find a single person who had the same problem that I'm having...

Help would be greatly appreciated...

Hello,

fix what?
Sorry, but iIt is impossible to help, if you do not describe exactly what happended, what you are seeing now, what version you are using, etc.
Please, refer to forum rules first.
Also check our FAQs.

Basically, whatever happened, if removing .htaccess did not help, there might be some conflict in code.
If you see no error message, check the webserver error logs. There should be some note about what happened. if you send us the error message, we should be able to help you.