On my way home, both my valve cover gaskets blew.

I wasn't doing anything out of the ordinary. I was cruising in 6th, when some white smoke blew through the A/C. Before I could get off the road, another puff of white smoke came through the A/C. I immediately turned off the A/C and got to a parking lot ASAP. No lights were thrown, nor did the car act weird. I popped the hood to see both valve cover gaskets hanging out (top portion). WTF causes that? I'm guessing excessive crank pressure, but I can't think of what would have caused it. I should note that the car started missing under load a couple days ago. I've been extremely busy and haven't had a chance to pull the plugs. I had no choice but to drive it today and babied it. It felt like I was partially holding in the clutch under 2k RPMs. Above that, it ran fine as long as I didn't get heavy on the pedal. I'm not going to drive it until I et it fixed, but what should I be looking for?