First, did the doctor do a culture? With a swab? Most likely, antibiotics are not needed (and why steroids???)... If so, did he say it was a bacterial infection, or was he vague about it?
Also, did the doc retract? That can cause it to be more inflamed than it origionally was...
You say it looks like a broken blister? Peeling skin? That sounds more like a yeast infection, which will go away with a 7 day treatment of Monistat (and an antibiotic will make it worse).
Does it smell bad? Most bacterial infections smell bad... Bactarin can be used on the genitals for bacterial infections. It's an OTC antibiotic ointment similar to neosporin, but safer on genitals.
Raw honey is good for infections on genitals, too.
Saline is simply salt water, and it is very soothing to broken skin, but won't really do anything (just keeps plain water from stinging, like in a cut, in the eyes, or on genitals)... It's good for cleaning.
Vinegar & water is good for giving a more acid pH if it is yeast. Baking soda baths are good for soothing broken skin or infections, but not so great for the pH of yeast.
ETA: Check out this thread on the first page of this forum-- Possible Seperation Issues/Pain/Sore/Red/Irritated/Ballooning/Normal Development,etc
because if the doc didn't do a culture, it is completely possible there is no infection of any kind and it is normal seperation issues.