I'm a cyclist suffering from inflamed gluteus minimus that seems to have gotten worse since stopping, what can I do?

Gluteus Minimus. Concern would be for continued subgluteal bursitis or possible tear of the hip abductor muscle. Begin anti-inflammatories for five days. If not improved followup with the person that made the initial diagnosis.
Find the cause. Confirm proper seat height. Be certain to do gentle stretches after cycling and consider the additional benefit of massage.
See an orthopaedist. That history sounds a bit unusual. Best to have an orthopaedist take a look to be sure the problem does in fact originate in the g. Medius. If so, physical therapy would be appropriate as a next step, possibly followed by a one-time cortisone injection if there is no improvement after 6-8 wks of pt.