Thanks for your question.
You have burning itchy rash on top of your feet.
You tried OTC antifungal medications & natural remedies without any relief.
If it is indeed contact dermatitis, then you need to apply potent steroid cream.
You can start with over the counter hydrocortisone 1% cream twice daily for a week.
If there is no improvement or marginal improvement, then you need to see your doctor for a prescription strength steroid ointment.