The sesamoids are two small bones underneath the big toe joint. When the soft tissues around them become inflamed, the condition is called sesamoiditis. Sesamoid problems often start with repeated motions of the foot and big toe joint. Athletes, especially dancers, are prone to this kind of injury. Your problem could have started from doing similar dance steps over and over again.
Treatment should include resting your sore joint. You need to give your toe a chance to heal. Until the pain and inflammation are under control, you will find it hard to regain your mobility and strength. Heavy use of your toe will keep the area inflamed and painful. It would be best if you lessened your work demands for a while, until the sesamoid problem resolves.