Problem with Photoshop brush

[Teekay]

My Photoshop brush has suddenly started acting weird. When using a soft brush, if I  click the mousepad it's fine but if I click and drag it expands as I move it. This isn't normal right?

I did take a video on my phone to demonstrate what it's doing but I don't know how to upload it here. 

I'll grab a screenshot of my settings though.

[Teekay]

[Damien Symonds]

To begin, try this: https://www.damiensymonds.net/2012/09/resetting-tools.html

[Teekay]

Well that was simple. Feeling a bit stupid right now.

I'd been looking for somewhere to reset the tool but I was clicking on the Brush setting icon. *Head slap

Thanks Damien