We just got back from our weekend at our trailer. We soaked all the ariators in CLR to make sure they were not plugged. Still no pressure. So as a last resort, we took out the filter to see what would happen and hooray, the pressure improved immensely. We soon discovered that the filter we had was too fine for our system. We talked to a plumber at the park and he gave us a different filter to try. Problem solved. We hope this will help someone else in the future.
P.S. Did I mention that we are "Newbies"?