this morning I tried to start my truck, it turned on for a second... chug chug then stopped. It was cold about 25 degrees, so I plugged it in for the day & still won't start. It turns over, oil gage doesn't move... HELP!

 

Is it safe to assume your truck has a diesel engine in it?
If so, a weak battery(s) and possible glow plug problem could be the cause.
Can you try a jump to help get it to turn over faster? If you can, try giving the batteries a charge. When the temp drops, all the low battery and poor cable connections seem to come out. I don't like to suggest starting fluid because with glow plugs that work, could set off the starting fluid unless you can give it a shot while the engine is actually cranking and the starting assist gets sucked into the engine.