Is it possible for me (female) to get poisoned/and or die from oral allergy syndrome (oas), anaphylaxis, or anything related if i were to eat a crab apple that i picked off of a random tree found on my university campus in a busy city?

You would only have a potentially fatal reaction if you were allergic to apples. If you are allergic to apples, you should avoid eating any apples, including the ones you can pick off a tree. If you don’t know if you have an allergy to the apples, then you should probably avoid these apples and eat apples you can buy to be certain you have no sensitivity. Good luck!