Thanks for your query.Based on what you have described it appears that you have multiple sebaceous cyst
over this area.This area is rich in more sebaceous glands than skin over rest of the body and so more prone to get sebaceous cysts which appear due to blockage of the opening of ducts of these glands. Most of the time it is self resolving but occasionally may increase in size to cause discomfort and may get infected .The fever
that you have may be due to one if these cysts may have got infected.Please consult some surgeon for examination and take antibiotics like Doxycycline along with some anti inflammatory drug like Diclofenac
twice daily for a week.If it does not subside then you have to get it excised in Toto by a surgeon.