How did Jennings overcome his struggles? What inspires Jennings?

Jennings overcomes his struggles through sheer will and inspiration from an unlikely source: a stuffed dog named Doggie. The stuffed animal doesn't originally belong to Jennings. Instead, it was the property of the Home of the Angels. The nuns hand out individual stuffed toys to the children at night.
After the children fall asleep, the nuns always retrieve the stuffed animals. For his part, Jennings took such a liking to Doggie that he eventually "adopts" the toy. Our protagonist endures many stressful life events with Doggie by his side. For example, when Jennings is taken to St. Teresa's, Doggie goes with him. The journey to St. Teresa's is a devastating one for Jennings. After his stint at the Home of the Angels, Jennings never expects to be sent to another orphanage.
The treatment he endures at St. Teresa's is far worse than anything he experiences at the Home of the Angels. Jennings suffers extensive physical and emotional abuse there. Throughout his experiences, Doggie is his only comfort. So, Jennings relies on Doggie for love and companionship.
Other sources of inspiration for Jennings are Sal (a bus driver), Sister Ann Catherine from St. Teresa's, and Officer and Mrs. Daily. The officer and his wife actually take Jennings in after he runs away from the orphanage in Yonkers. So, Jennings overcomes his struggles with the support of Doggie, as well as several compassionate individuals in his life.