Like everyone has said you probably weren't going fast enough, but as imporant is keeping control over the main in a spinny-less gybe, if you just let it crash over it the force of the main suddlenly powering up will have you over. Always control the main, sheet in and travel in coming into the gybe and ease it out slowly coming out of the gybe, this means you have control to de-power out of the gybe and you don't have a large open head of the main shoving you down the mine.

Pepin i think you have the wrong approach to the traveler, it's a sail control that can be used very efficiently when racing. Upwind in big breeze and chop its often worth wile to ease some traveler to be able to bring the bow down slightly to punch through the chop while still retaining main tension. Also its not fast to go round the windward mark half submerged or taking a very wide berth, dropping some travler means you can turn more easily and quickly and have more control if the bow does go down and as important it's much easier to pull a few foot of trav up rather than metres of main back in.