And Rotty daddy would you detail more about not flying the same as off tow because I try to control the plane the same way.
What I meant was: you can't always do what you would do if, say, you were off tow following another glider, and wanted to stay behind it in the same relative position you would have on tow. With 9 flights, you should already know about this. Maybe this is not your problem, but I will elaborate briefly, just in case...
An example: let's say you are higher on tow than normal, and way off to the left. You want to get back on center,at normal "high tow" height. If you were free and just following the other aircraft, you could just make a coordinated descending turn to the right. In a glider on tow, this will not quite get the result you want... you will more than likely wind up speeding up a bit, slacking the rope a bit, then overshooting your target spot laterally before you can stop the banking and descending. It would turn into a series of S-turns, nose going up and down all the while, and the tow pilot would probably think you were losing control and would hit his release to get rid of you.
If the towplane were to turn while you were doing this, it would be even worse (picture it).
So the right way to fix that particular position problem is to first and foremost use rudder to get back to center, keeping the wings more or less level. The resulting skid would get you descending with very little if any elevator input, and the drag would also tighten the rope, which will tend to pull you back towards the center.
Speaking of which, consider how you move up on one side while boxing the wake: I guess different gliders vary, but in the Schweizers I fly, I usually have to actually hold a little "outside" aileron to keep from getting pulled back in as the glider slows from that small pitch-up needed to go from low corner to high corner. Doing the same thing off-tow, you would not need this.
In short, the dynamics of the rope have to be considered... you don't need to understand it completely, you just have to remember you are being dragged along at the end of a rope!
As stated by others, you pretty much ignore the yaw string on tow- most of the time, when changing position, you will have rudder and ailerons uncoordinated.
As for following the towplane in turns, that's usually a coordinated turn, but the timing is important, and matching the towplane's bank angle is pretty much the secret to success there. If you are boxing the wake during a turn, or get out of position by accident during a turn, your best bet is to do what you muct with rudder and elevator, but be sure to
keep that bank angle the same as the towplane's!! Still, though, if the towplane tunrs, and you are early or late, even if you match the bank, you may find you are tunring "inside" or "outside", not following the towplane's path through the air. To fix this, you need rudder, primarily- don't change the bank angle trying to chase the towplane! It's OK to skid or slip a little, if needed, during these turns... it's not OK to start S-turning all over the place. Basically, in turns, you fix your position the same way as in level tow flight... only thing that's different is the horizon looks tilted.
You mention over-reacting... maybe in general you're just moving your hands and feet too much. There's no magic formula to fix that; just work on applying only what's needed, only when necessary, and it will get easier for you.