Good suggestions above- also try to bring the rig over your head to windward. This depowers the sail and makes it easier to sail in high winds and bigger sea states.
To achieve this you need to really sit down in the harness.
To make visualization clearer, think about how you sail in light winds- you want to stand the rig up right to give it more power- well sailing in op'ed conditions, its just the opposite.
In addition, try adding more downhaul and more outhaaul to depower to sail as well in addition to lowering the boom and moving hte mast foot forward.