The Rebbe advises a Rosh Yeshiva to continue his vital role despite the personal cost to his own study, as the benefit to the many brings divine assistance. He encourages strength in his mission and urges regular study of Tehillim, Chumash with Rashi, and Tanya, as these daily lessons are spiritually beneficial.
https://www.torahrecordings.com/rebbe/igroskodesh/015/010/5528