OP, if you're familiar with adb and adb shell, google the Reparted method. If you're careful you can rebuild the internal partitions via adb shell. You'll need a printout of the stock Vibrant partition structure, you should be able to find that on google as well. I'll post mine here as a reference for you, but I recommend doing your research.
Do not partition through recovery, that'll just make things worse. If you follow reparted though, and carefully cause you can do more damage if you don't follow the steps correctly, that can help you out of this jam.
Hope it helps there OP, don't hold me responsible if you make it worse, but this is my best guess at what can help you.
EDIT - here is the printout from my Vibrant for the partition you need to fix, best of luck.
Model: MMC MAG8DE (sd/mmc)
Disk /dev/block/mmcblk0: 16.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flag
1 32.8kB 14.0GB 14.0GB primary fat32 lba
2 14.0GB 16.0GB 2013MB primary lba
You ride yourselves over the fields
And you make all your animal deals
But your wise men don't know how it feels
To be thick, as a Br1cK
- sign up and we both get free space!
only if you really feel its necessary.