Seems like you have plenty of supply so no need to pump every 2 hours! Especially if you latch baby there's no need to pump at all, pump only as a replacement for baby's meal. Sleep is definitely more important, though you should be careful not to let it get too engorged or you might develop mastitis which is not fun. I think sleeping 4-5 hours in one go is fine, but if you sleep longer than that you will need to wake up, pump or latch then go back to sleep.