[Rain]

So in which food do we find pterocarpus?
 I see on the internet its very hard to eat such thing,because its part of a tree?

You can't get everything over the internet. 
What you got over the internet is the source of that spice.
Pterocarpus is a kind of Indian spices commonly called "khathai" in Hindi. It is usually defines the sourness of food, but it is not for that purpose. It stimulates and represents under growth hormones.
Foods are many such as prepare cheese with vegetables with certain amount of "khathai".

Its something Ive never heard of before, and I actually still dont know what it is.. if i google pterocarpus it also brings up sandalwood? Would that be a usable source as well?

I goggled khathai and came up with green mango powder, which he is saying has pterocarpus (i think).

Bonny is reaching exactly to the point that is green mango powder, but i have used pterocarpus here because for breast enlargement it is impure mixture of green mango powder with powder forms such as sandalwood. It contains more than 94% of green mango powder and other powders. It's available in market or check the link.  https://www.spicejungle.com/amchoor-green-mango-powder

Howmuch should you eat per day ?