My SUV suddenly dropped oil pressure and is leaking a lot of oil. Is it something simple or?

if it all leaked out fast than the plug came out. or if it's been leaking slowly you need new seals. it is not expensive to fix unless you try and run the engin now with no iol in in. you may be able to fix it yourself if to plug just needs to be tighten. then fill it with oil. not attemp to drive it with low oil it will blow engine.

did you have any work done lately? there is no such thing as a sludge plug you mean did the oil drain plug come out? its possible as well as a double gasket on the oil filter or a broken oil hone or a blown motor all of these are possible

Your going to have to lift the bonnet and look where the oil has come from. DO NOT drive it again as you will cause engine damage. The sump could be split or the sump plug may have come loose but it also could be a multitude of other things.

If the oil pressure dropped then the engine will not be lubricated properly , get it checked out before you do some serious damage .