I've been having atopic dermatitis for 2 years and it's always comes and goes. What is the real cure for it?

Eczema triggers. There are many triggers for eczema. Allergy to dust mite, pet dander, foods, fungal or staplylococcal skin infections etc.Your best bet is to seek evaluation from an experienced allergist or dermatologist who is interested in finding these triggers and not just offering to treat the symptoms with steroid creams.