Have you tried calamine lotion, or other good brand body lotion?
It’s possible it’s the fabric of your clothes. I know Dacron and polyesters fabric will make me itch, but all cotton is fine. Also wool can scratch the skin, making you itch.
Maybe it’s the detergent you are using? A good dermatologist might help you.
Do you have dry skin? Is it worse in the winter when the heat is on?
Hope you get some relief. Bug bites can also cause itching.