OP try Simple or a completely unfragranced soap for a couple of weeks. It’s often the fragrances that set off skin sensitivities. It can take up to a couple of weeks to settle down if your skin is being set off by fragranced or harsh products.
If it continues, you can use Diprobase emollient lotion (OTC) as a wash in the shower (don’t bath so that your vulval skin isn’t sitting in water and soap. Don’t use any kind of bubble bath or bath fizzers/bath bombs).
Rinse your vulva carefully after using any scented soap/shower gel/hair products elsewhere on your body, too (these can drip down and irritate even if you think they don’t).
Buy an unscented laundry product (eg Surcare) for any underwear or laundry you wear next to your skin.
Buy some unbleached, reasonably sturdy loo roll that doesn’t have any aloe vera/oil/added lotion and doesn’t shed fibres everywhere. Sometimes loo roll can cause irritation or lots of bits of lint which irritate the skin.
If you have periods, switch to unscented organic “cotton” style pads, or period pants washed in unfragranced laundry liquid. Avoid tampons for a bit.
Check and treat if necessary for thrush, Bacterial Vaginosis, threadworms. BV, an imbalance of vaginal flora, can also cause sore skin and itching.
Finally, how old are you? Perimenopause (or indeed extended breastfeeding), in fact low oestrogen generally, can cause sore and thinning vulval skin. If it doesn’t resolve in a couple of weeks with unfragranced products and/or plain water, book a GP appointment to look at the vulva - they can also refer you on to your local hospital vulva clinic.