I have been shocked many time. 110 volts mostly. The key issue as Dav0 said is, You were shocked in one hand. If you were shocked by one hand to the other hand or hand to foot, the electricity would flow across your chest and be a greater risk. That fact that is was momentary and caused you to pull away indicated the low level of shock. More intense shocks can cause muscle spasms that prevent pulling away.

It only takes 0.1 amps to stop the heart. But, that usually means an across the chest shock.

The mechanics of your shock are simple. You touched two prongs on the plug. It does not matter whether the light was on or not. The extension cord was still live with electricity. It is important to think of the prongs as deadly so one is careful to not touch them as one plugs them in.

And, sweaty hands create a problem as they increase the conductivity of your skin and reduce the grip strength as you plug things together causing one to use an unsafe grip on the electrical cord.

The safest way to connect an extension cord is to unplug at the wall, connect the cord to the appliance/light/tool, then plug into the wall receptacle. Otherwise, just be careful to only touch the plastic, not the prongs. If the extension cord is not plugged in, you can safely touch the prongs to straighten them so they fit in the plug.

And remember, with PCS, you have a heightened startle response. An electric shock will trigger your startle response in a big way. It can take a while for the body to settle down, especially if anxiety builds.

It sounds like you will be just fine as soon as you get your anxiety settled.