No you should not break it. However you may not need to stand on the centerboard if you weigh that much, just reach up grab it and pull it down. I can right mine with no problem and I weigh 135 so I don't think you will need to stand on the centerboard.
YOu're certainly not going to break the board off- YOu can if you get the mast stuck in the mud however...
The best way to not tip over is to keep the floaty part (the hull) under the part that wants to tip (the mast). Sounds obvious... but downwind -when it's really blowing the dog off the chain- (the only time you'll really ever tip over) this is how you need to steer. It's called steering for balance in the world of real dinghys (International 14's, 49ers, 505s.) When the mast goes over one way- just steer the hull underneath it and that's it. Like riding a bike- You can't actually crash if your wheels are still between you and the ground. So just keep the hull between the mast and the water...
Fortunatly C14.2's don't really tip over that often unless it's really blowing. So I don't think that flipping is much of a worry. But you should be prepared anyhow.
When you do tip over the (this is alot like 12 step programs...) the first thing to realize is that you're tipping over. The rudder isn't even in the water anymore- what are you still doing hanging onto the tiller??? If you are young and spry you can make it over the high side and onto the centerboard without ever getting wet. College sailors and laser sailors do this drill all the time.
If you're not so spry and not so experienced to realize that all is lost you're best off going for a swim. Be a man- jump in. No sucking. The more you hang onto the boat the worse things will get for you, and the more the boat will turn turtle. The mast and sail will stay up for quite awhile without going turtle. The reason the boat goes turtle is that some sucker is still hanging on. Hit your crew with the tiller extention if they are still hanging onto the boat. Usually the skipper is the heavier of the two people on the boat so the skipper should swim around -quickly- to the CB. Of course as soon as your get around the transom you'll realise you tipped over cause you had the clunk in the trunk in the first place going downwind and when things got squirly and you flipped--- well you didn't think to put the board back down. So get the crew to uncleat the thing and pull the board out. Next grab onto the end of the CB and put your feet into the lip on the gunwale. This will give you some leverage. This also helps you get more of your body out of the water without having to use all of your arm strength. Unless you regularly do pullups with wet clothes and are a total gym rat there is not much chance at all of you actually making it onto the centerboard. If you really need to make it onto the CB you're only going to get a few chances at it anyhow before you're cold and fatigued. All the while your crew should just be hanging out getting tangled in floating lines between the boom and the hull. This is a good place to be surprisingly enough because the boat won't blow away from the crew. This is also a good time for the crew to uncleat everything like the mainsheet and jibsheet and make sure that the righting goes smoothly. Capsized boats will blow away downwind WAY faster than you can swim so it's important for the crew to not get separated. If you're actually on top of the cb and when the boat comes upright just jump over the gunwale back into the cockpit. You're done! Mostly however you're not going to be up on the board so you'll have to do some more swimming...
Actual mast hitting the water until the boat is righted should take about 15-30 seconds. Remember the faster you go the better.
One really good reason to have the crew on the 'low' side of the boat is that as the boat is righting they can hold onto the gunwale a bit and slow the boat as it comes right side up. You've probably seen boats get righted and come up so quickly they flip right over the other way. If the crew is really savvy they can hang onto the hiking strap and get 'scooped' into the boat as it comes up.
One tip for folks with little experience in tipping over. Don't even try to climb into the boat over the side. You'll just pull it over on yourself again anyhow. Climb in at the transom. The boat won't want to tip over on top of you- and your crew- if they've been 'scooped'- can walk to the back of the boat and grab you by the lifejacket straps and pull you in the boat. If you try to climb into the side of the boat your crew will have to be on the other side of the boat- for counterbalance- they won't be able to help and you'll still have one heck of a time getting in the boat. And for you single handers or not so strong folks you can put a loop of line about 5' long through the aft hiking strap eyestraps that you can pull over the transom to put your foot through to help you get up into the boat unassisted.
Don't tip over in the first place.
Admit to yourself you've made a mistake -go swimming.
Move quickly to right the boat
Climb back in over the transom. (This really makes it easy)