mroberts
As a frequent passenger on airlines since 1978 and a private pilot, maybe I can add a little to the explanations already posted by PT Gamekeeper.
Stalling an airliner is a very serious matter and it is highly unlikely that you experienced that.
The air being fluid and all that means you will experience some bumps and bangs if you fly enough and they generally feel worse than they are, due to the inner ear being designed for terrestial use
Go arounds are quite normal (typically happen several times a day at very busy airports) and often happen because (a) air traffic are not happy with the horizontal distance between two aircraft ... this is not because it is dangerous, but rather to maintain safe separation or (b) because the aircraft is not stabilised in landing configuration at a key reference altitude. PT G also quotes some other examples.
Although somewhat disconcerting when you encounter it for the first time, it's nothing to be alarmed about and the crew will be appplying the principle of "aviate, navigate and communicate", so they may not be able to make an announcement to let you know what happened quickly, as their workload in going around and then setting up for a new approach will be high.