If you roll your ankle inwards then can't stand on it for 10min now have bruise ans small swelling its painful but I can walk on it what have I done?

Ankle sprain. Sounds like an ankle sprain. The canadians tell us that if you can walk on it and don't hurt when pressing on y the bones then you don't have to get x-rays unless it persists.
At least a sprain... You definitely have sprained it. Using rice (rest, ice, compression, and elevation) for it can help over the next couple of days. Ibuprofen or Naproxen are good anti-inflammatory meds to take over the next number of days also (better at reducing swelling than tylenol (acetaminophen)). Having point tenderness (sharp pain with pressing on a spot) can sometimes mean fracture. Hope you feel better.