1996 Jeep Grand Cherokee Oil Pressure Gauge Problem?

My 1996 Jeep Grand Cherokee is a V8 converted to 2WD. It's not by any means a new vehicle and has had its share of problems. I've replaced the axles, various sensors, the tires, and other small parts. Recently the problems have included the Oil Pressure gauge falling to "zero" and the "Check Gauges" light comes on along with the beep. The Jeep has 163k+ miles and the previous owner did not take perfect care of it. I've been keeping up with oil changes, routine maintenance, etc. My first thought when the light came on was to check my oil to make sure I had enough, I took the dipstick out and it was well coated in it. As far as I know that's an ok way to check your oil level. The HUD keeps popping up with "Coolant Sensor Bad", could this be related or is it just bad timing to get hit with both? I need this vehicle to last as long as possible and I do not have much money so I need to know if there is anything I can do to fix it. I bought some oil, a funnel, an oil filter, and a coolant sensor so I could try to fix it. If anyone knows what could cause all these problems please let me know. I really can't afford to take it to merchant's and pay them a hundred bucks just to tell me whats wrong with it. Thank you.1996 Jeep Grand Cherokee Oil Pressure Gauge Problem?
I have the same year and model jeep, except still 4WD. I have the exact same problem. Hope someone can answer this.

oil change