That is definitely where you went wrong. When you partitioned your sdcard, you erased everything on it. You're gonna need to get an sdcard adapter so that you can transfer the files back from the computer.
Do not, DO NOT, flash DangerSPL. It is for G1s only.
ETA: DangerSPL didn't cause the problem, it's just unnecessary for the MT3G. Gawd only knows why they don't make that more clear in the install guide.
Also ETA: Depending on your Recovery Image, you may be able to ADB push your files back to the sdcard from the computer from recovery.
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