An hour or two with an instructor who doesn't have a lot of stall/spin/aerobatic time is unlikely to help much.
STIK,
Quite unusual for most aircraft not to spin one way or the other without dancing on the rudders. If you've time to dance on the rudder you've got time to release the back pressure on the stick which is the actual cause of the circumstances you find yourself in.
I believe the key for the final turn is bank angle. Way back when I started gliding I had it knocked into me 'well banked final turn', 'MINIMUM 30 degrees'. This came back to me during commercial training, all turns in the circuit EXACTLY 30 degrees.
So what is the point?
Well, in a glider there is a lot of wingspan which, if you try to cheat, helping get the last bit of turn with a touch of rudder or just fly inaccurately, creates a considerable difference in airspeed over the respective surfaces. If you're already to slow this may be the final nail in your coffin. If you fly too slowly through a steeper turn you get a high rate of descent and the nose drops but all you have to do is level the wings and you're flying again. One way you die, the other you live.
In the commercial training the point was to improve your judgement so that you only made the exact required turn instead of 45 at 30 degrees, 30 at 20 and the final part of the turn at 5 or 10 degrees.
My gliding and training remain fresh in my mind; when I do a visual approach, coming in on base or from 45 degree base, I still wait until what I reckon to be the right moment to make the 30 degree banked turn instead of waffling onto the final course.