Are you working with a doctor and did they concur with your diagnosis? Usually they examine and look at the appearance and if you have discharge they swab it. It depends on what is going on as to what they prescribe. There can be infections that would indicate an antibiotic choice. Have you switched soap to make sure that isn't aggravating it? But if you aren't better, then yes, see your doctor for follow up care and change in treatment.
Oh, a nurse practitioner is a medical professional so that works. However, if you are unsure of their advice, they normally do work with doctors in the office and you can consult with an actual MD as well. You did the right thing to change soaps. But what I don't know is if you have an infection. And depending on what they think the bacteria is causing the infection, that would indicate which antibiotic to try. Amoxicillin is a good all around antibiotic but don't self treat. Have a doctor prescribe and follow your case.
This is fairly easily treated - use a topical antibiotic ointment along with your antifungal. Bacitracin works wonders. I'd recommend getting it with lidocaine as well in order to help any associated pain. Follow up with a moisturizing lotion. It's important to apply this after showering. If you can, I would recommend applying it 3x daily.
It typically clears up in a couple weeks.