propane problems

I had problems with my 20 year old propane regulator, so I put on a new one two weeks ago. It worked beautifully. Yesterday, I got a propane refill. Since then, I have had problems. At first there was no propane getting through to any function. I decided to tap the new regulator in case something inside was sticking. Since then, a very small amount of propane has been able to get through. For example, I can light one of the stove burners, and it will light, but go out due to a lack of propane in about 7 or 8 seconds.
Anyone know what I can do? Do I need another new regulator? Was it overfilled? Would poor propane have caused this? I am at a loss, and I am an amateur when it comes to anything mechanical or technical.
Help.
Ken