There's no right answer, unfortunately. I only have questions.
If you didn't have the unexpected bill, would you have considered borrowing against your stack to buy more BTC?
(Status quo bias means we are often willing to take poor gambles to avoid a loss that we wouldn't have done to make a gain.)
And if the hype cycle peaked now for whatever reason and BTC then dropped back to its lowest price in three years, could you survive financially whilst repaying the debt?