Hi.. I Delivered A 2.6 Kg Baby At 38 Week

hi.. i delivered a 2.6 kg baby at 38 week of pregnancy before 22 days...after 1 week of his birth he was 3 kg and after more 1 week he was only 3.2 kg... his length at birth was 49cm . he looks too weak... he is suffering from jaundice when he was 4 days old.. still his face is yellow and has rash on his face. his hands and feet are white ...he is on motherfeed and intake after every two hrs.. i am worried about his weight.. he is too weak ..please advice me some tips to.make him healthy.. thank you