Lightroom Brushes completely gone

Im very upset with this program right now, for a multitude of reasons. I even upgraded my computer and somehow it seems like things are getting worse. It's SO slow, I mean screen going black with the spinning pointer once every few minutes, brushes not even covering all the space I've drawn over by the time the program catches up to where my pointer is and skipping, having to optimize my catalog every 20 minutes and reboot at least 5 times a day just to be able to click on something and it respond less than 5 minutes later, slow. At first I understood because the file I was working on first had begun to collect over a dozen masks, but now im working with files that haven't even been touched before and on the first mask I'm having serious problems. I mean, I honestly don't even know what to do. I upgraded my ssd and ram, purchased a cooling pad, changed all my settings, have NO other programs running and even clear unnecessary processes in task manager. Im working on a folder with 40 photos in it, only two of which now have more than three masks. Today, while working on a jpeg, for whatever reason I got to a certain point in my edit when suddenly the program literally would not let me go any further. If I changed any setting at all or added a brush stroke it would just revert to the original photo, settings, masks, and all. The only way to undo it would be to undo the previous step. I reinstalled my driver, rebooted Lightroom, rebooted my computer, deleted the preferences file, and it still did it. Thankfully because it was a jpeg I could just save it where it was and import the new jpeg but if I was working on a raw file I would be absolutely screwed. 

And now, my brushes are gone. I was literally using them 2 hours ago when I closed my screen to step away and I come back and they've just vanished. They aren't in Lightroom, they aren't in the folders, they aren't even in my backup folder in my documents. They're literally all missing, I can't find them anywhere, and have no idea how Lightroom could have even done this or how to fix it.

Today has taken me back so far in my work and I don't know how I'll even recover what's been lost.

I feel like I can't trust the software anymore and it's incredibly disheartening. I couldn't find any help online so I'm here now. Has anyone else had this happen and how did you get your work back? How do I prevent Lightroom from ruining what I've done and deleting my files?