Gassy and sad baby question

Kittery16

Can't believe I have been BFing for 2 months and am just now realizing that food I am eating is hurting DD   I feel absolutely horrible

I looked online for foods to avoid... the list was so extensive that I don't know what I CAN eat.  I know that every baby is different and I am sure all of the foods listed don't upset her tummy.  I just don't know what the best way is to determine which foods I need to avoid.  Do I start from scratch with foods that are really bland and basic?  Keep a list of my intake and compare it to her fussiness?  Any other ideas?  TIA ladies!