Producer counter-claimed star was trying to leave contract after rape allegations
Over 53,000 supporters join campaign to release singer from her deal with Sony and Dr Luke
Singer is seeking to be released from contract after claiming to be raped by her former mentor
The pop singer is accusing her producer of 'mental manipulation, emotional abuse and sexual assault'
Coyne says he sensed a degree of 'anxiety about their relationship' in the past
Pop star contradicted new lawsuit she is filing against producer and song-writer
The letters were written during the singer's rehab stay earlier in 2014
Singer is suing her producer and mentor for emotional abuse and sexual assault
Kesha signed with the producer when she was 18
The singer has been in a Chicago facility being treated for an eating disorder