Hi, Skinner and welcome to the Forums! I'm sure you'll get some good advice... the first thing I'd check would be to take the shower head off and make sure it doesn't have any 'stuff' in it. Sometimes flashing from plastic, or small pebbles from the water supply make their way into the fixtures. I've cleaned lots of small rocks and other bits of 'stuff' out of faucet screens over the years. You'd be surprised to find out how little 'stuff' it takes to reduce the water flow.
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"