Hi dear,I had gone through your question and understand your concern.You should be worried ,but not too much. He can adjust to school gradually,at the first leave him for 1-2hours, then take before lunch,then after lunch.Usually during 1-2 weeks they become independent. Better that grandmother or father drop to school and mother takes from school,then baby will not cry for mother. There will be only more risk. for infection. But you should give sanitizer daily.You can give multivitamins-Zincovit. 5 ml daily for prophylaxis of infection