Two immediate possibilities.
1. It's become magnetized, perhaps you had it very close to a large speaker or amp. If this is the case it's an extremely easy fix with a cheap demagnetizer from eBay, or a watchmaker do it with theirs for a few bucks.
2. With all the percussion you've knocked the regulation arm inside the movement so it's moved too far into the fast position. This is still an easy fix, but involves a little more work.
You'll need a timing app on your phone (I would suggest Timegrapher if you have an iPhone), a clean toothpick and a steady hand to shift it back to the correct positions. There are two levers, one is for beat error, one for adjusting rate/speed (see photo), possibly both may need adjusting if you've really knocked it around.
Google regulating a mechanical watch (lots of tutorials). You want a beat error as close to 0 as possible, anything under 0.5ms is considered acceptable, and the rate again as close to 0 seconds as possible, but with an older 2609 and it's your first attempt at this anything within +/- 20 seconds per day is probably fine. The timing app on your phone will guide you as to how you're going, use small adjustments each time until you get to where you need.
Do be careful though, if you use too much force and slip and hit the hairspring you might damage it.
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