Speaking in Nick's interview with Dr. Phil McGraw, Michelle said: "He has blamed himself for the condition she's in. He has said to me many times that he is going to kill himself. Two weeks ago, he tried... He was able to throw up pills. He cannot bear not being with Krissy, by her side. He's dealing with it by drinking."
Nick's mum also opened up about the events leading up to the incident on January 31 and confirmed the pair had got into a heated argument the night before after the handsome star returned to their Roswell home from partying with a pal.
She explained: "Nick walked away from the argument. He went to another bedroom to fall asleep. [Bobbi] went up to her room and drew a bath."
Meanwhile, since recording the interview, Nick - who claims Bobbi's father, Bobby Brown, has prevented him from visiting her in hospital - has checked into an unnamed treatment facility.
He promised Dr. Phil before checking in to rehab last week: "I'll be clean, I'll be sober, I'll be a good person."
However, Bobbi Kristina's aunt, Leolah Brown, recently slammed the TV interview, claiming Nick is being investigated for "attempted murder" and it could interfere with investigations.