Oh hun that is so horrible. She's in the best place to get the care she needs. Make the most of getting it off your chest on here and with your sister and friend. You'll have waves of ups and downs. Definitely don't go into work, you need to get yourself sorted first.
I know it's a bit different but I understand your emotions - I sadly lost my father last Christmas while I was pregnant and during his battle we all went through so many emotions, but the best remedy was getting it all out, whether it be crying, ranting, laughing or therapeutically smashing stuff!!
Stay strong for your Aunty, and let your guard down and have a good cry when with others who will support you.
I hope she is ok sweetie and hopefully they will let her home soon, but not before she's ready.
Sending hugs xx