If there's any silver lining to this, it's that your mother didn't have a long, miserable decline, as so often happens to our old folk. And she was treated at a time when there's still spare capacity in the system, so you can be sure she was comfortable when she lost her battle. So sad not to be able to be with her, but my recent hospital experience with my own mother showed me that although staff can be very busy, there are always a few really wonderful folk on every shift who take their patients to their heart and treat everyone as if they were family members. So your Mum died among the extended family which is our NHS.
92, as you say, is a very good innings; same cohort as the Queen. She lived through so many changes, so much world drama, so much evolution of society and life. But her watch over human history is over now. She's at peace, and everything she ever taught and shared with you lives on in you. She's safe from life's troubles, but you are not, and the very last thing she'd want is for you to waste one moment wondering if she caught it from you. Life is wonderful, random, and often rather cruel. So be kind to yourself, and try to remember the last time you heard her laugh.
Oh, and firebomb that car, it clearly has it in for you!