What is with the toolbar?

Toolbar on the left disappears into the top of the screen and I can’t move it down or disconnect it anymore, so I can’t change the size of the brush or eraser. Which means now I’m stuck and can’t continue any of my projects. I’ve logged out, turned my computer on/off, etc. and nothing has changed. wtf?? I can change the brush and the color, but not the size of the brush or eraser. It’s all stuck on one size.