You have developed Pityriasis rosea
It might take upto 6 to 8 weeks to heal.
You can use topical steroid
cream for relief from itching.
No direct role of sunlight.
Disease is self limiting in nature, so do not worry.
Lesions might continue to appear in crops for sometime.
You can take oral antihistamines along if there is too much itching.
Hope it helps
Dr Geetika Paul