So sorry to hear about your losses.
I'm 71, and finally getting it that loss is a part of life, as I get older. Doesn't make it any easier, but . . .what can one do? Accept, kind of like the Buddhist idea of suffering, though I have to say some days it is really hard.
You've probably read about it, since you're a librarian and read a lot?, but I've read that there is what some have called an epidemic of loneliness in our society currently. So, we're not alone, in our aloneness, if that makes any sense. Sucks, but there it is.
I'm sending you all the love and acceptance and best wishes that I can, through this limited medium of internet support. It does help me sometimes, glad you reached out.