This is a serious situation, and I am not qualified to give medical advice.
Important Reminders
Wild animals should not be handled. Possums can carry diseases and may bite.
Maggots are a sign of a serious infection that requires professional veterinary care.
What You Should Do
1. Do not attempt to remove the maggots yourself. This could cause further harm to the possum.
2. Contact a wildlife rehabilitator or a veterinarian specializing in wildlife. They can assess the situation and provide appropriate care.
3. Keep the possum safe and warm. If you must handle it, wear gloves and avoid touching the injured area.
Remember: If you find a wild animal in distress, seek help from professionals.