I'm a novice sailor myself and had difficulties tacking in high winds also. Are you letting the main out as you turn into the wind. In light wind it's not that big of a deal but in heavy wind if you don't let the main out the sail tends to "weather vane" the boat into the wind putting you in irons. When I tack in heavy winds, right when I feel the main start to luff I let it out, go easy on the tiller, and of course let the jib backwind. But I haven't mastered this either, I still seem to go into irons at least once in heavy winds and of course it's usually at the worst possible time, like when I'm near a dock or another boat.