Well, I'll give it a shot. Here is what I would do.
1. Confirm you are delivering CO2 to the keg. To do so I would turn the gas off, pull the pressure relief valve and wait until almost all pressure is gone. Confirm that your gas line is hooked up to your in post on the keg. Then turn your gas back on and listen. If you hear gas entering the keg then you know you are delivering CO2 and that side of the keg is not your problem. (I am going to assume that you did not accidentally install your dip tube on the gas in side of the keg but you might want to check this)
2. If number 1 checks out ok then you most likely are clogged somewhere on the out side of the keg, including your beer line and faucet. If you have another keg you could try hooking up your beer line to that keg. If it pours you would now know the problem is in the keg itself on the beer out side. You could do one of two things at this point. 1. Hook up your gas line to the beer out side of the keg to try and dislodge anything that got stuck. Or 2, pull the out side post and dip tube out of the keg and clean them.
Good luck.
