Yeah, after a while it turns out it wasn't a problem with the program, but with the mouse instead- there was apparently some dust under the mouse button or something, causing it to misbehave. Thanks for the help btw
example image of what im talking about
holding the left mouse button down, drawing letters and they come out as this. dont really know how to explain it other than with this image
also disabling "fluid mouse input" makes it even worse