It seems that you have hurt the ligament of the larynx while trying to stretch your "esophagus"
Throat has number of ligaments the help in maintaining the structural integrity of the throat. Of the ligaments larynx forms an important component. The larynx is a special part of the body that functions as an airway to the lungs as well as providing us with a way of communicating (vocalizing). These functions are all possible because of the skeletal components and the muscles that act on them.
The trauma to the larynx can cause shortness of breath and also pain during swallowing as this helps to communicate both the esophagus and the trachea. IT also get infected and inflamed which may cause fever.
I would recommend the following-
1) Avoid digital manipulation of the structures in the neck as it can cause complications. They are one of the most sensitive structures on the body. Make sure you do not touch it any more as you may inadvertently increase the infection.
2) Get an Extended neck X ray done just to rule out any complications like fracture and retropharyngeal abscess. Retro pharyngeal abscesses a life threatening condition that occurs due to g=digital manipulation of throat. It leads to collection of pus behind the throat and may require immediate surgery.
3) Take tab. Tylenol or tab. ibuprofen to reduce the inflammation and to reduce the fever.
4) If there is constant rise in the temperature or constant increase in pain, consult an ENT specialist for a thorough physical.