Respectfully, it's you who's been misinformed by viral but false monetary theories. It's true that the US government can't run out of dollars in the same way that you or I might run out of dollars. It's not true that the government has no fiscal constraints, or that taxes and spending are unrelated parameters.

> The interest is interest we choose to pay, for some reason.

Perhaps this is the best point to talk about, because the precise way in which it's untrue is very concrete. The US government doesn't choose how much interest it feels like paying; it sells securities which promise a specific payout schedule according to an auction-set interest rate. If investors want to buy at a high interest rate, there's no mechanism for the government to demand they accept a lower one.