leaky bottle!!!

here's my delima, I hope someone can help me out here. I just picked my truck up sunday from having the suspension redone. I've got 1 four foot nitrogen bottle for right now, waiting on the second one. I barely hit my switches, and my bottle is already empty. It was empty yesterday, I have been cutting it off, when I'm not in the truck, but it seems to leak out faster when I cut it off, and if I leave the truck aired up over night, if it's cold outside the whole truck leaks down, but if it is warm outside, just the front leaks!!! I really don't know where to start, i have never ran nitrogen, and the last suspension setup I had sucked ass, so I really don't have a clue where I need to leek first. Sorry for the long thread, but I hope someone can pint me in the right direction on this. Oh, and I only turn the regulator up to about 150 lbs of pressure, so it's not like I'm trying to hop the damn thing.