I assume many of the oil type fruits have some lecithin, such as olives, etc.
I have no clue what the problem would be with soy lecithin as far as your not feeling good. When people use herbs and don't feel good, many times they just don't like the reaction of their own body cleansing and of course who knows if your having an allergic reaction.
"IF" your problem is with soybean lecithin, then you would not be able to eat many commercial foods, because it is in much of the foods people eat.