while trying to resize my brush or zoom in/out, Photoshop automatically zooms in/out as I slide my b

Have you tried a mouse, sounds like a tablet sensitivity issue.

Are you using any modifier keys at the same time as the brush?  It is normal for the brush size to change if the Alt key is held down and the mouse dragged left or right, and hardness to change when move forward and backward.  It sounds like you might know that, so is it possible that your left and right mouse buttons have been reversed?  It sounds unlikely, but it is possible.

What are your Preference settings for Zoom?

Your wording is just a touch ambiguous, so can  you describe just the one action and reaction at a time?  Just so we know exactly what we are looking at.