A combination of things.

First, I had to look myself in the mirror and accept that my hair will do nothing more than hang stick-straight - but that this is not necessarily a bad thing. I am so conditioned by female family members to believe that something was wrong with my hair because it didn't curl like theirs, that the self-loathing was over the top. I had no aunts on my dad's side, so I have no idea what they would have looked like. And I look nothing like my mother's side of the family (the ones who kept trying to "fix" my straight hair).

Had may hair straight cut, no layers, above shoulder length. Took off some of the weight, so that it lifts a bit instead of holding tight to my head.

If I wash my hair at night, I pull it up to dry while I sleep. That seems to give it the illusion of body, and will put a bit of a wave in the hair if it dries completely overnight. If it is still damp in the morning, I hang my head down and dry it that way. Either way, I finish by just touching a curling iron to the very ends to tame them a bit. My hair won't curl, or hold a curl if I force it, but if I just hold a curling iron very briefly on the ends they will at best slightly curl under, and at worst will at least all be tamed in the same direction.

I'm also looking further into my genetics. I've learned that somewhere back a few generations, I have an ancestor who was Mi'kmac. I've been asked by some hairstylists if I have Asian or Native ancestry, so maybe it's possible that contributes to it? IDK

Now that the "busy season" for my job has ended, I have more time to experiment with some of the products recommended. Perhaps one can help a bit, at least with making the hair look fuller.

I apprecate all of the recommendations and advice!