A dark and strange spot irregular in shape above my foot appeared for nearly a month, red soft blisters keep appearing and pooping on that dark skin?

Athlete's foot: The lesion is likely just athlete's foot but its difficult to diagnose a rash sight unseen. Your best bet is to see a podiatrist for a proper diagnosis and discussion of treatment options.

Melanoma: Dark irregular spots that arise out of no where, you have to rule out melanoma or skin cancer. Go see a podiatrist or dermatologist have them do a biopsy of the lesion. They can also tell if it's fungus or a spider bite or eczema, an allergic reaction. Don't delay especially if the dark spot is getting more aggressive looking.