My baby ia 1 year and 3 months old. And he is a g6pd defficient.and is very painful while feeding.

I'm sorry, I don't quite understand. What is a g6pd defficient?

my baby ia 1 year and 3 months old. and he is a g6pd defficient.and is very painful while feeding.

Any obvious signs of damage... cracking, ridges, tender spots? Sharp, burning pain? Is is painful for a bit after a feed as well or only while he is latched? Has he been teething? Have you been ill or have any infections recently that you used any meds or creams for? Any previous episodes of painful feeding? Has he been on any new meds recently?

Might check both of you for possible thrush (while often there will be white patches in the child's mouth, it doesn't have to be evident).

Try a bit of breastmilk before and after each feeding and allow to air dry. If one side is more sore than the other, might try pumping the sore side for comfort and have him feed just off the other for several feeds in a row.

Because of the g6pd, are you avoiding potential problem foods/meds as well? Any related effects for him from birth, for example due to high bilirubin levels?

You can probably find pure lanolin at a family owned pharmacy. Gently rub the nipples with the lanolin several times a day and after feedings.