Right now I mostly fear that I will make no lasting connections with other human beings besides my family. I have a few close friends but I feel time is slipping away. I feel very alive and ready to connect with people. I want more lasting friendships. Looking back there is a huge chunk of my life where I was not interested in dealing with people in a substantive way. I fear that I will die without showing people who I am really am, and that I love them, and that I am available.
Surviving to old age. Also, that I've missed a turn somewhere and so am not where I should be (which begs the question of whether there is such a thing as fate, about which my personal jury is still out.)
I'm trying to confront it gradually, as I expect it will happen - that my husband will die several decades before I do, of a very nasty disease. It's happened to all the other men in his family, and he's ten years older than I am.
Also, going deaf, because widowhood will be crap if I have no music.
Variations on the usual. That I'll never have a non-related person who chooses to love and be loved by me. That I'll lose everyone I love, and I won't have loved them as well as I should've. That I'll lose my vision completely and will basically be at the mercy of others whom I'll have to pay to care for me, and that they'll resent it and me anyway. That I'll have wasted my mind and my energy on things or people that would have been just as well off without me. That I'll die and that the strongest emotion anyone feels will be annoyance that they have to clean up my apartment.