I saw that nobody had responded.
So sorry about your partner.
I know my mom has this (she is not that old, but she's not young) and she's tried a lot of different things. If you are looking for something natural, I can't help, except to say that I use nut butter on my face every morning and night (and I do have combination skin, but if I'm consistent and it's clean when I put it on there, I don't get zits) and that does even out wrinkles and plump up skin. I don't know if it will work for crepiness.
Put the oil on when skin is moist and it should be an oil that absorbs "neat" if it's a massage oil. I like Kukui Nut Oil.
Other than that, yeah, sleep. Maybe someone here knows some natural sleep aids?
I *do* know that skin can heal so it does not have to be a permanent change in your skin, so don't worry about that. When the grieving runs its course and you are able to get more sleep, your eyes can also return to normal, or at least improve.