Ok , I was driving home yesterday and about 1 block from my house my car starts to knock from the motor. the oil pressure gauge went down but it is still full of oil. i only drove it for less that 1/2 mile like that . does anyone know what this could be , is my car messed up . any advice/help would be greatly appreciated

 

Probably a spun bearing if you hear a knock and have no oil pressure.

 

is that a big deal to fix

 

Well if rebuilding your engine is a big fix then yes.