Popped bone out in wrist, got myself a wrist support brace and put it on loosely and now my thumb has been numb. Do I have nerve damage? In pain.

Yes. You have a fracture or dislocation of a wrist bone that is now pressing on your median nerve. You need to see a hand surgeon asap before you have permenant nerve damage.
Maybe. If the bone that popped out injured the nerve, that could cause nerve damage. Otherwise, the splint may be too tight and compressing the nerve. Make sure it is the right size or loosen. Also, if you popped a bone out, you need an xray.
You should. See a hand specialist immediately. Either in his office or the er. You may have nerve or vascular compromise that would need to be corrected right away to prevent long term damage.