Loss of power and sputtering

It started out just randomly sputtering and running rough at take off, and has progressively gotten worse. It is now dying and wont idle for more than 30 seconds to a minute. I started by changing the fuel filter, that seemed to help for just a short amount of time, it was still not right, but within thee same day it was back to bad again. Then I found a vacuum leak on the elbow going to the fuel pressure regulator, no Help at all. I added a can of seafoam fuel cleaner, and a fuel tank of fuel. It is still progressively getting worse. I noticed that after rechecking the new elbow on the fuel pressure regulator that fuel came out of the regulator. I then replaced the Fuel Pressure Regulator. Still no help. At this time the vehicle will not stay running long enough to drive it.This has all happened in a span of one week. My next thought was to check the fuel pressure. Any Help would be greatly appreciated. Thank you