Operation Epstein Fury seems to have heavily relied on assumption that killing Khamenei and a few other high-ranking officials would cause the Iranian government to fall apart and riots to erupt again, giving them the country on a platter. So they literally don't know what to do now, hence Trump scrambling to pull out while saving his orange botox face.
You should give the West more credit than that.
The strategy does not require a quick victory. It just requires one of two things: 1) the regime to fall, or 2) the regime to sue for peace, giving up nuclear weapons in the process. Either will result in objectives achieved (degrading Iranian military infrastructure, killing key leaders).
The only condition for defeat is if the Iranian government neither falls, nor sues for peace, but is able to mobilize the country in an all-out war effort that forces the US to put boots on the ground and/or develops nuclear weapons. This is however unlikely. We've seen no signal that Iran is capable of a general mobilization or that if such a mobilization happened, it could successfully capture territory under constant bombardment by Western forces. We've also not seen evidence of Iran getting closer to nuclear weapons under the pressure of constant precision strikes.
The reality is that Iran might be angry, and people might now support the regime more, but it can't really do much.
The scale of damage to the global economy might be greater than Trump initially expected, but since he likely got his friends to short the market before hand, it's not going to really affect his interests.