Why did I receive an electric shock from my microwave?
This is why GFCI sockets are used in kitchens. 

It sounds like you have a bad ground circuit or possibly switched hot and neutral wires on the sockets.

Time to call in an electrician before someone dies.

My congratulations on your survival, we once lived in a house that developed some sort of issue that caused the cold water tap outside the front door to be hot. I found out about the bite and dangers of electricity when I was 5 years old.