The Rebbe expresses hope for a full recovery and urges the writer to take upon himself to publicly teach Chassidus—on Shabbos and at least one weekday—regardless of audience size or level. This strengthens his connection to the Rebbeim and serves as a channel for healing and blessings.
https://www.torahrecordings.com/rebbe/004_igros_kodesh/iyar/1005