Mike, here's a little trick you can try to see if it helps. When it's really blowing hard, try pulling up your daggerboards a little bit (6" if racing, more if just practicing) when going up wind. This will settle the -up- hull down in the puffs, it won't fly as quickly so you can keep better control of the boat.

The single most important thing you need to do is to see the puffs coming down the lake, and prepare for them in advance. Unclete the main and be ready to ease it as the puff comes on, and try not to round up into the puff as that will just slow you down. Try to keep the up hull at a constant height and try to keep driving in a straight line, ease the main when the puff comes on then trim it back in as the puff passes.

Every time you wiggle the rudders, you are putting on the brakes, so try to keep a staight line. (look back at your wake to see if you are going straight).

Once you get comfortable doing this with the boards up a bit, then put them back down and do it some more. There is no substitute for practice though, so get out and sail it as often as you can.