I get cyst-like things around my panty like even with loose undies. these are very painful and when they burst its greenish-gray pus and blood.?

Hidradenitis: Hidradenitis suppurativa (hi-drad-uh-ni-tis sup-u-ra-ti-va) is a chronic skin inflammation marked by the presence of blackheads and one or more red, tender bumps (lesions). The lesions often enlarge, break open and drain pus. Scarring may result after several recurrences.

Carbuncle: May be a result of ingrown hair that is getting secondarily infected. Warm soaks should work, but to prevent a good waxing or depilatory can help prevent recurrence.