My mom has cancer

My dad died very unexpectedly 7 months ago, we believe of a heart attack. I was the executrix of his estate, so on top of grieving, I also had to deal with the enormous responsibility of managing the estate. The my dad’s house finally closed last Friday, and on that day, my mom called me and told me she has cancer. I am completely devastated and I am having the thought “I can’t handle this.” I am so worried she will die too. I want very much to deal with this from a place of integrity, but I don’t know where to start.