I made a mistake to comment.
I love Gaga so much respect and love this song that has nothing to do with anything.
Why did Gaga get credit?

Credit: VALERIE MACON/AFP/Getty Images
Maybe because … Diane wanted to ensure her support in promoting the song.
Gaga is a very smart business women she knew a song written by Diane Warren.
As Lady Gaga and I have [consistently] said.
We made some changes so it would speak to more people than just rape survivors.
The song kind of became a conversation between two women whod been sexually abused.
She was saying, I want to share this with you; this is ours.
And thats what were saying to people: We want to share our pain with other people.