I am so sorry to hear about this latest development.
When my father went through this (lung cancer, though), his doctor gave him and Mom same kind of warning/heads-up. It was about three to six months before he passed. Nobody knows for sure about timing, of course. It does seem a little callous at the time. However, in the near future, you can help your parents make sure all necessary paperwork is in place for this final transition. It may be for hospice care, wills, POAs, etc., and anything else that will make things easier on your mom and you when the time does come.
Of course, miracles can/do happen, and I certainly hope for stabilization in your father's condition. But, thoughts are with you in any event. So sorry about this. You and Mom will get through it.
Thank you for your kind words. I’m sorry to hear about
your father. May he be resting in peace ❤️