Dear Almost Doctor, being a medical student i am surprised by you choosing to post a question here rather than consulting with a dermatologist at your hospital. Get it checked and consulted from a dermatologist as the foul smelling cyst (as you call it) needs to be assessed for need of I&D (incision drainage) . Also as you report these abscess are forming frequently you might need a workup for checking your sugars and the scars of previous lesions need to be assessed to rule out conditions like hidradenitis suppurativa.