Okay so, this only applies to this site. I can open other websites and they load either instantly or in a timely manner. But e621 pages will take several upon several minutes to load. And this long loadtime can sort of "spread and infect" other websites.
I haven't tested this with other browsers, as I have no others installed.
I have umami installed. If the problem stems from that, let me know and I will move discussion to the appropriate thread.
This seems to only affect the database itself. Forums are on-and-off on being affected.

If you have any help or advice or just know how to figure this out, please let me know.

Are you using mobile or desktop? Regardless, try clearing your browser's cache.

Instructions for clearing your cache are available at these two pages:
https://support.mozilla.org/en-US/kb/how-clear-firefox-cache
https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox

If the issue persists, try disabling Umami and see if that makes a difference.

song said:
Are you using mobile or desktop? Regardless, try clearing your browser's cache.

Instructions for clearing your cache are available at these two pages:
https://support.mozilla.org/en-US/kb/how-clear-firefox-cache
https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox

If the issue persists, try disabling Umami and see if that makes a difference.

I am using desktop, I use The Wolf's Stash for mobile, which works flawlessly.

I'll try clearing the cache, then disabling umami.

song said:
Are you using mobile or desktop? Regardless, try clearing your browser's cache.

Instructions for clearing your cache are available at these two pages:
https://support.mozilla.org/en-US/kb/how-clear-firefox-cache
https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox

If the issue persists, try disabling Umami and see if that makes a difference.

Yes, it was the cache. I had over a gigabyte of data in it. Everything loads instantly now! Thank you!

arousedunderling said:
Yes, it was the cache. I had over a gigabyte of data in it. Everything loads instantly now! Thank you!

Saying "spread and infect" makes a lot of sense. It was the clue that tipped people off that it was a cache thing.