Everything in the fuse box in the engine bay works but I don't think that I'm getting power to the fuses in the cab. Both of the main fuses (in the cab and in the engine bay) look fine, so I'm wondering where I need to look to see what is disconnected. Please help me.

Unless you have been messing with your electrical, the power running to your fuse box should be fine. For the fuse box in the cab to be disconnected, lots of stuff has to not work including:
All interior lights (except the dome)
Windows/locks
Gauge LEDs (open door, seatbelt)
Stereo
...

What's not working?

Everything you just mentioned isn't working. No interior lights except the dome, no brake lights, no tail lights, no turn signal but I do have the emergency flashers, no stereo, no door locks, no windows, no gauges glowing, no tachometer or speedo, etc. Everything in the in-cab fuse box is off.

Wow. Okay, then any idea where your line could have been severed? Were you playing under the dash? Under the hood?
I haven't had to mess with the lines going from the battery/alternator to the cabin, but I know Coomer has. He could probably describe the places you should check.

Okay, does anyone know where the feed wire is that runs into the fuse box under the dash? Anyone that knows please help.