Thanks for your query.Based on the facts that you have posted it appears that you have developed Fordyce spots
on your scrotum
since last six months.
These are due to accumulation of sebum beneath the skin and normally fade away of their own without any treatment.
However some times they get infected .
The swelling and redness
of these spots suggest infection.
Please consult your family physician and get prescription for broad spectrum antibiotics. It should get cured in a week.