Saudis are not silly, they don't give anyone a dime for free. As far as Iran , since 1979 Pakistan and Iran has no trade relation. So, its pointless to talk about Iran interest in Pakistan. Pakistan can't even buy a litre of oil from Iran ,just to keep Saudis happy, those who are making billion of dollars from Pakistan from selling oil. Otherwise Pakistan has lots of other options to buy oil from market. So, don't feel so merciless and miserable. Saudi made billions from Pakistan and trade balance totally in favor of KSA. You feel so much pain cause you lived all your life in KSA and your sympathy for them is understandable.
Look at India, which buy 90 percent oil from KSA and 10 percent from Iran. Plus getting 70 billion investment in future in India, all top jobs and even now they are inside KSA and UAE bureaucracy.
Think about national interest of Pakistan first.