OP, you don't need it to be an actual bathing suit. Not if you don't want it to be. I'm your age. I'm much more comfortable in swim capris, any capris length parachute-like material pant and a T shirt (also called a rash guard if you get one specifically for swimming). More coverage, more modest. Why do women have to expose so much more of their bodies than men? Women's bathing suits are so much more revealing. I mean you can if you want to. But don't have to.
I can't imagine how capris would be comfortable - all that loose wet fabric would drive me crazy. I find the same thing with skirted suits.
How do you conclude that women expose so much more? I think that's true of women wearing bikinis, but a one piece for women doesn't expose any more than swim trunks on a man - a woman's top is covered but there is leg exposure, while a man has legs partially covered but entire torso bare.