Cow's milk alllergy to LO

Nancy
Hi guys,
It seems like my little one has cows milk allergy. Though doctor has not confirmed but lo's crying has improved a lot since i stopped dairy. I felt guilty that what did i missed during pregnancy that has caused it. I paid proper attention towards my eating during pregnancy. :(
Can anyone share their experience with this allergy and how long it wil stay? They say usually it outgrow in one year.