Hi, thanks for your query.
You are taking appropriate steps to treat sunburn
In addition you may use a moderate potency steroid
like momatosone for a few days twice weekly on the rash
You may take oral antioxidants
and beta cartene by prescription.
Avoid further sun exposure till it heals.
It may take another couple of days to settle.
Hope this helps you.
Wish you a speedy recovery.