Hi
It sounds like you panic when you get the ball in an attacking zone - as you're under pressure from defenders and need to make snap decisions.
There is a simple way to fix this, which, if your coach was worth his salt, should have noticed and fixed by now - put 15 cones down in a straight line like this:
o.....o......o......o etc etc with 2feet distance between them, practice dribbling between them, however, the important point to learn here is to keep your head UP, do NOT keep looking down at the ball - also, do this exercise barefoot - it vastly improves your control of the ball. Start it slowly and build it up to full pace. The important thing though is to keep the head up - that way you are always looking for the pass, and also can see the defender coming earlier and thus do not panic as much
BTW i dont mean DONT look at the ball EVER but try to keep the head up as much as possible.
Balance - simple balance beam exercises, and also by keeping your head up while dribbling the ball will help this because you're not leaning over the ball and off balance as you will be by looking at the ball.
Beating a player - the easiest way to beat a player (and hardest to defend) is to change direction and speed at the same time - if you've isolated the defender 1v1 - then slow down (not to jogging, maybe to 3/4 pace, and then as he approaches push the ball either side of him (change your direction by roughly 10 degrees or so... if you get my meaning?) and sprint instantly - the change of speed and direction will mean you will get the ball past him - its up to you to have the ability to get that ball back, if not, then win the foul by going over their outstretched leg
There are lots of fancy dan tricks but if you're running at pace, none of them are effective. If stationary, or moving slowly, a Cruyff Turn (google it!) is very effective, but only when outwide.