non-plastic bras, tights, shapewear, etc?

i’m trying to remove polyester, nylon, acetate etc from my wardrobe/life. not just for sustainability reasons but also for sensory issues, the materials just make me feel horrible and sick to touch (i’m autistic).

most of my clothes are cotton and linen but i don’t understand what the hell you’re supposed to do about the other bits and pieces.

bras, tights, shapewear, anti-chafing shorts, activewear, swimwear, etc - where do people find these that don’t contain plastic? i’ve only been able to find loungewear-style cotton bralettes, but as a 38G my boobs are not staying in or getting any support from those.

i’m in the uk btw.