Carissa does feel terrible once she takes the headband off but she decides to ignore this; if she's might only have weeks to live it's some kind of unimaginable horror to spend a minute of them sulking. She looks over her to-do list, instead, to see how many of the items on it still seem doable.
She wants to reach out to Osirion and see what they know about the current statue of Cheliax and Project Lawful. She suspects it'll be less than she hopes, because probably they were spying directly through Abadar, but conceivably Abadar's still at it, or they have other channels. She wants to talk to Erecura and maybe Dispater. She wants to figure out if confidential negotiations with Abadar and Iomedae are possible. She wants to publish cult pamphlets for drop-off in promising locations. She wants to pressure-test her Abrogail-assassination plans and maybe run them by Ri-Dul, who seems like the kind of person who has contemplated how he'd assassinate Abrogail Thrune.
She wants to write a long angry letter to dath ilan about how they are the worst, in case this is actually a work of dath ilani fiction and she can influence them that way.
She wants to play with sixth circle spells, even though she's never, ever going to grow powerful enough to cast them herself.
She wants to write a letter to the children she would someday have had if they'd gotten to exist, which they won't.
After that, whatever, she'll make headbands or something.