Hi Feary,
I don't know you or your situation, but I do know how it feels to be terrified of growing old and dying. It consumes every moment of every day, so to live "in the moment" really "S**ks!! It seems like there is no way out of the viscious cycle. For me it comes in waves. The anxiety gets so bad then ebbs away leaving me exausted. I try to rest, and it comes back. Sometimes I go through this cycle four to five times a day! Medicine doesn't help. The only thing that has helped me is a book that a dear friend gave me. "Feeling Good" by David Burns helps me calm down by just reading the section on anxiety and panic attacks. I can't change my circumstances, or the way I feel, but I can read the comforting words and they help. Also, I hope that by coming here and reading posts like yours and others, I'll feel better. I appreciate it that you are willing to write about your experience so I can feel less alone.
Please take care of yourself.
Whimsical