As a life long all-over eczema sufferer I can sympathise.
You should also consider food allergy. I found I was allergic to cows milk protein at 21, after all those years of horrible eczema, strong steroid creams, a skin infection so bad I couldn’t bear wearing clothes and that nearly put me in hospital.
I’ve been so much better since (now 36). I use Diprobase daily and a moderate steroid cream to control the odd flare up.
I still have a constant but background itch. I take antihistamine every day to help mute it. Stress, sweat, cats are all triggers for me but the milk allergy is the main one.
See if your doctor can get you some blood tests for allergens. Good luck and stay strong. Oh and don’t scratch!