Could someone explain to me what wing loading is? Every once in awhile when I'm fighting and have someone on my six my plane seems to just run out of energy and is on the verge of a stall even though my airspeed indicator says I'm going 200 or 250. It usually happens when I'm on the deck and trying to make a sharp turn to the right of left in order to get a scissors going for a overshoot. It's like i'm completely out of power and the plane just feels like a brick.
I suspect this has something to do with wing loading but I'm not sure. I'm usually into the flaps a notch or 2 and she just won't turn. The only way to bring my plane out of this is to just straighten out and buildup speed, but this just leaves the enemy with a good gun solution.
It seems I have good speed but not the energy to maneuver. I've always thought that speed basically is energy. But sometimes that doesn't seem to be the case. 
Wing loading is the loaded weight of the aircraft divided by the area of the wing. Sounds like your issue might be too much AOA. Try easing off the stick a little and see if you get a better turn. Pulling harder only increases your turn up to the point where pulling harder decreases your turn.
That is the answer to your wing loading question. The question you need to ask and have answered is Why am I stalling in a turn even though my airspeed is 200 to 250 MPH. The answer is you are experiencing an accelerated stall. The best example is the dive bomber pilot , diving in on his target at 400 MPH , releasing his bomb and pulling hard on the stick to pull out of the dive. Pulling so quickly and so hard that his aircraft does nothing but continue its head long rush down.
Stalls (the ability of the wing to produce lift) has nothing to do with airspeed. It has everything to do with Angle of Attack (AOA) and relative wind (the angle at which wind (air flow) strikes the leading edge of the airfoil). When the AOA becomes excessive, as in a hard turning flat turn and you are pulling a lot of G’s no matter what airspeed you are flying if you exceed the AOA for the relative wind present , the wing will stall.
Don’t miss understand what I am saying. Any aircraft needs a minimum airflow over the wing to be able to fly and we measure that airflow with the airspeed instrument. At any airspeed the wind will develop Lift. When you go fast the wing develop excessive lift and can climb.
As an exercise you may want to try flying and practicing the Accelerated Stall. Climb to 5000, fly straight and level maintain 5000 and reduce power, slow the aircraft until the stall warning begins to chirp. Note the airspeed, you are very close to your power off stall speed. Now add full power, as the airspeed begins to climb raise the nose about 15degrees and roll into a 60degree bank turn left or right and pull back hard on the stick, the AOA will become excessive and the wing will stall.
What you should see is the airspeed will be well above the power off stall speed of the aircraft. Reinforcing the fact that airspeed does not cause a stall, excessive AOA does. The high or outside wing will stall and the wing will drop, you should end up with wings level and the nose level. Now place the controls in the stall recovery position. That’s no back pressure on the stick perhaps even nose low and the rudder centered. Adjust power as needed to maintain level flight.
Notice that the stall recover does not include application of power. That is because a stall recovery is not performed with power, the elevator is the only control needed to recover from any form of a stall.
