You sort of have to piece it together yourself.S
What is the true story, or where can I find it?
Start with looking into the Marines that were there and and what they planned before the SEAL got involved, then you can look into the footage that the "Taliban" (not really taliban but who gives a fuck) shot themselves.
Then look at what the Marines did in Operation Whalers.
You can also read an account of the Afghani guy that saved Luttrel but I'm not sure how truthful it is and haven't read it personally.