This pain can be complex. If it is Ischeal bursitis (rest (avoid sitting on it, too - perhaps "sit" on recliners that get you to zero gravity on the sit bones), ice, anti-inflammatories) is possible but you could also have some piriformis syndrome, too, (a modified form of sciatica where burning / cramping, etc. can occur; stretching will help this). Many people posting here actually sound like they have piriformis syndrome moreso than bursitis. Stretching and exercise (walking, some squats), helps but avoid overly repetitive exercises (i.e. perhaps not running, running up hills, etc. You can do squats / leg press with some weights once in the rehab phase - but avoid over repetition).