The Rebbe reassures him that Hashem, the essence of good, guides the world with hashgacha pratis, so worry is needless. He encourages public Torah study, especially the halachos of Tishrei, and to serve with joy and gratitude, remembering the light of Chassidus and living with confidence and simcha.
https://www.torahrecordings.com/rebbe/igroskodesh/015/013/5757