How much longer can the Iranian economy survive?

Someone in the Trump administration must surely have worked out that at a certain point Iran's economy will be so dire because of the continuing US Navy blockade that the tough Tehran regime will be forced on its knees to beg for a deal with the US. That moment, it seems, hasn't come yet, but when will Iran's economy collapse totally without any income from the billion-dollar oil export business? No oil is leaving Iranian ports. Tankers are being barred from going anywhere, and those that try are being hit by missiles in their engine compartments. So, why isn't Tehran already begging for mercy? Will it take another month, another six months, another year? Donald Trump is not going to wait that long. He wants to escalate the pressure on Tehran by returning to bombing. But actually, with a little more patience in Washington, the Iranian economy will tank beyond repair and some sort of deal will be inevitable. With patience, the highly successful naval blockade cvuld do the trick. More bombing is unecessary and will only inflame the Middle East further. Patience is what TRump needs. But Trump is not a patient leader. He wants results quickly. Quick results is something Trump has singularly failed to achieve.