Sudden Low Oil Pressure

[Satva1100]

i had just replaced my oil pump with a melling high volume and i had like 60psi at idle and everything was good for a week or so and then after a race my oil pressure was only 19psi at idle and about 35 to 40 when driving. why did it all of a sudden do that, i have 565RWHP on a stock block and stock oil pan, did i blow another oil pump or what?