I will pray. My brother went through a bone marrow transplant for his leukemia and survived by a miracle from God.
Many of the toxic meds for the transplant are very hard and painful on the body, can cause hallucinations, etc., and can really make a person feel as if they are going crazy. At least, he should still be in a hospital where others can keep an eye on him.
Leukemia (without being treated) will cause a slow and painful death. With the transplant, this young man has absolutely no immunity, and hopefully, there is no infection trying to set in.
Keep praying, God can still work miracles. You may not be allowed to see him, but, send a card, a prayer cloth, anything to take his mind off the isolation that he has to be in.
God still heals!