I suspect @Tomoe_To has tried to customize the brush in some way.
@Tomoe_To: Which brush are you talking about? Did you change your old brush and overwrite it in the Brush Editor with the lower of the two buttons at the top right instead of saving it as a new brush with the upper button? That can be undone.
If in doubt, I can also offer you your brush for download, if it is a Krita standard brush, or a brush from one of the many bundles I own, if its license allows it.
From your meaningless generalizations, we can derive little to nothing to help you. That you have tried everything is great, that may even be true, but it would only help us if you told us what that “everything” was, because as you can find in countless places in the forum: “We don’t have a magic crystal ball (which is currently operational), we’re not allowed to read the minds of our users anymore, and we’re not sitting next to you watching what you’re up to!”, so if you need help, then you need to put us in a position to help you at all by providing us with your information.
We don’t know what you have changed on your brush, nor do we know what you have tried to undo. The same goes for the tutorials you have watched, what are they about, if they are in English then it would be good to give the links to the tutorials you think are most important so that we can get an idea of what your problem is.
We also need a screenshot of your entire Krita window, with status bar and title bar, which represents your problem, a sectional view is sufficient in case of doubt if you cannot/may not show the image in its entirety. The layer docker must be visible and the layer you are working on must be selected. The “broken” brush must be active and the Tool Options docker must be visible in the foreground and fully expanded so that we can see all the settings displayed in it (which is not much with a “Freehand Brush Tool” brush (with other tools used, such as the selections, it can become a lot more)).
What do you mean by you have “plenty of storage”, it points to HDD but with your English I’m not sure if you mean RAM and also not if the space is free, and do these masses also have a numerical value that allows a statement about their size, metaphors don’t help any of us to help you. And 8 GB of RAM is anything but ample or even comfortable, but is only slightly above the absolute minimum of what Krita needs.
I can’t say when I’ll get back to you, I’m fighting an infection and have a fever, but your answers and the screenshot will also help the other helpers to support you (a screenshot is not a photo, photos don’t help us, if you don’t know how to take screenshots ask Google and Co).
Michelist