12 pounds in 9 days is pretty big, especially if you are already in shape. Just watch what you eat and get in at least 2 workouts a day, one in the morning and one in the afternoon, and one in the evening if you want.
But if you can't make it just go up a weight. I know a kid who wrestled 135 during the season and was trying to make 130 for Fargo (
Dustin Schlatter was at 135). He couldn't make the last 2 pounds so he went to 140 and got 3rd in the nation.
If you start eating right and lifting you can go 66 (or is there a 63kg class for the tournament). It may not pay off immediately but in the end it will most likely be worth it.