Thank you for your query at DoctorSpring.com.
I understand your concern.
It appears that your foot is infected following the rupture of blisters. Parasitic infection is unlikely. It could be infected with Staph or any other bacteria but the good thing is, with a proper antibiotic course and wound care, you will be cured.
The risk of infection increases if blisters are popped. So more than the exposure you had earlier, the infected would have resulted after you had popped the blisters. And more than the heels, footwear that is uncomfortable and poorly fitting can lead to blisters. So please make sure you only wear comfortable footwear for now.
I would recommend that you take the following measures.
1. Please consult your GP for wound evaluation and appropriate management, including prescription of antibiotics. You may require to take tablet Augmentin 625 mg, twice daily for 5-7 days.
2. You can take an OTC Ibuprofen 400 mg, twice daily with food, for 5 days. This will reduce the inflammation as well as the pain.
3. After cleaning your foot with an antiseptic liquid like Chlorhexidine, you can dust Neosporin antibiotic powder over the wounds.
I hope this was helpful.
Feel free to ask queries.