high oil psi issues, helppp

hey there. I have a 1987 Subaru gl here with high psi readings consistently. It doesn't overheat at all it just builds high pressure instantly. Maybe a bad oil sending unit? Don't really know where to start here if it is. Where is the oil sending unit on this vehicle? I have gauges not a light if that makes a difference. Thanks!

A grounded/bad sensor could cause the gauge to peg.

so I just started it and drove it after idling for a minute. The gague sat at 45 until I revved the engine then it quickly rose to 75. I drove it for a minute with the gauge reading 65 on avg. It seemed responsive to what I was doing so I'm not sure its the gauge. I opened the hood an saw all my radiator fluid was leaking out of a hose and something else. I'll take pictures to show where its leaking from.