Suddenly having a TON of different problems with my WordPress install

Okay, all of the sudden WordPress totally sucks. I don’t know if this is related to 4.1, my site, some plugin or what, but I would love any input.

Here’s the laundry list of issues that have made publishing make me want to smash my skull in with a hammer.

1. Constant error messages when trying to upload images. The last one I saw was something stupid like busy now, try later.
2. Open the Add Image function on a post and the image library sometimes doesn’t even show any images, yet there are thousands of images in said library.
3. The same goes for the Insert Link function. Sometimes, no links found, despite their being thousands of posts on the site.
4. Inserting an image into the body of a post — sometimes it will insert, sometimes it takes five tries.
5. Setting a featured image — pretty much the same scenario.
6. Comments — I will approve them, navigate to a different part of the admin and then see that the very comments I just approved are indeed still listed as pending.
7. The good old blank, white screen. Sometimes I’ll publish something and instead of going to Post Published, I get a blank, white screen. The post does indeed publish, but I have to refresh to actually see this is the case.
8. Inserting Twitter links. These are supposed to automatically show the actual Tweet. Sometimes they do, sometimes there’s just a Twitter link in text form.

This is not user error stuff. Something is maddeningly wrong.

Please let me know if you have a suggestion or know what the issue might be. Everything on the site is up to date with the latest versions.