I want to first let you know that you're doing a great job at treating your baby's jaundice, don't give up. I see that you're already showering him with the yellow flower water and sunning him, these do help. Do take note not to keep him under the sun from 11am-4pm as it gets too hot. You can sun him twice a day, in the morning and late afternoon between 4pm-6pm (this timing is also good for brain development). Another thing that you can try to eliminate are items in the diet such as ginger and traditional herbs like ginseng, until he gets better.
Also, what so you mean by you do mixed feedings of 1 to 2 FM a day? Do you mean you mix 2 different types of FM, or do you mix feed him with EBM and FM?
Shuk Yi