You seem to have developed occipital lymph node swelling due to the skin infection
over the scalp
Since you have developed several pus filled lesions over the scalp, firstly you should stop using oil over scalp.
Wash hair daily with an antidandruff shampoo.
apply a topical antibiotic
cream over the lesions twice a day.
You might go addition need a course of oral antibiotics
Take some pain killers for the associated discomfort and pain.
Hope it helps
Dr Geetika Paul