The singer was stunned by the shock departure of drummer and guitarist brothers Josh and Zac Farro in December 2010, and initially felt sure Taylor would follow, leaving just her and bassist Jeremy Davis in the group.
She told Alternative Press magazine: "When Josh and Zac were leaving, me and Taylor weren't close at all.
"I was pretty sure that it was just going to be me and Jeremy. I was really scared Taylor was going to leave too."
However, the 'Careful' hitmaker was overjoyed when Taylor approached her and told her he wouldn't give up on the band.
She added: "Me and Taylor went to a show and after we went out to eat and he was like 'You know I'm not ready to go anywhere. I still have more to do in Paramore'.
"And after I just got in my car and cried and then wiped The Tears away and thought 'Okay we're going to be all right'."
Josh and Zac were heavily critical of Hayley and the group's management as they left, but have since said they wish the band â which continues as a three piece â well in their career. The brothers have since formed new band Novel American.