As Fourstroke and Bruce have said, not touching the ailerons most likely caused the crash. With a low wing plane fully deploying left rudder may well 'cause' the plane to roll right.

Think of it like this, most of the rudder surface (if not all) is above the thrust line, (or center of the plane), when you apply full left rudder not only will it push the nose to the left, it will also be trying to push the right side of the plane down. You have to compensate for this by applying some left aileron.

On a high wing plane with significant dihedral, that dihedral compensates for the rolling induced by rudder.

As Bruce said, leave the rudder alone once the airplane is off the ground, and use rudder as your primary control for turning. Once the plane is at a safe altitude adjust your trims, then play with the rudder. I think you'll find that the affect it has on the plane is significantly different than a high wing plane.

Good luck with the next one.
Dennis-