Yikes! based on that story you may have ruptured a thumb tendon or damaged the sheath/pulleys that it tracks along. Out of curiosity, does your bruising and tenderness follow this
tendon tract? (that's a right hand, seen from the palm side)
Don't waste a trip going to a walk-in-doctor; go to one of the main hospital ER's as you'll likely require an MRI/ultrasound followed by a plastic surgery consult. If you've torn the tendon, you'll need surgery semi-urgently -
before the tendon scars over permanently!