iPod only works while plugged in?

Hello, my iPod touch got wet when I got caught in the rain. I dried it thoroughly in rice, but now it only works while plugged in. The display will tell me that its charging, then fully charged... and all apps work perfectly and at full functionality while plugged in. Then as soon as I unplug it, it shuts off.

Also of possible importance: while plugged into a wall, it works perfectly, but while plugged into a computer it flickers as if its struggling to get enough power.

Any idea what component of the iPod could be causing the problem?