progressive tingling numbness in left hand fingers thumb

four weeks ago I was cutting the lower small branches off my oak tree.  I felt a slight sting on the very tip of my index finger.  Then I noticed many wasp galls on many leaves, but I do not know if that is what stung me. supposedly, gall wasps dont sting so I dont know what it was.
About the same time frame I swung the water hose towards me and the nozzle hit me really hard on the wrist area about 2 inches from the wrist towards the elbow on the same edge as the thumb. The next few days I was very aware of numbness on my index finger tip and a flat dry spot appeared.  I never got a blister.  The spot was 1/4 inch in diameter.  Since both of these events, the numbness has moved down my finger and now includes my thumb and  to a lesser degree of numbness my middle finger. I am starting to feel it progress to my ring finger (next to the pinkie) and also past my wrist at the point where the nozzle hit my forearm.  
Very rarely, that hand has "locked up" at the knuckles but this has happened before either event.  
.  My question is do you have any ideas what could be causing the numbness.? it is really irritating but I dont want to go to the doc if I dont really need to.

[Dr Sharma]

Hi there. This appears to be sensation loss in the median nerve distribution in the hand due to the injury from nozzle of water hose. Consult a neurologist who will assess the nerve function and conduct a nerve conduction velocity test NCV and electromyogram EMG. Depending on the severity and degree on nerve damage, the nerve regeneration would occur. You need to be monitored for function periodically. Consult a physiotherapist to help you with function of the hand. Hope this helps. Take care.