Whoever said "Wing Stall" almost had it right. In fact, it was right, but I call it a tip stall. When you went into that left hand turn, your left wing lost lift so the airplane turned to IT'S left. Which is where the ground was. When you are coming in for a landing, remember you are right on the edge of stalling the airplane. You should make your turns really large when flying slow (and with flaps, I think you had flaps on in there) and you need to use your rudder just like with a helicopter.
Use this one as a learning mistake. It happens to all of us.
Once you have made your turn and you are on final approach, lower your throttle under 25% (it will vary with each plane, I cut the throttle on my 3D planes, but I have no flaps) and bring it down slowly. Once you are about 5' off the deck, keep reducing throttle and slowly add elevator to flair and scrub off speed. Your plane will gently (or should) lower it's self to the ground.
I hope this helps and I HOPE YOUR HAPPY!!! Now I want to fly my planes hahaha.