Lea Michele "completely broke" after Cory Monteith's death.

The 38-year-old actress - who shot to fame playing Rachel Berry in 'Glee' - dated her co-star from 2012 until his shock death from a heroin and alcohol overdose in July 2013, and not only did she find having to grieve in the public eye "so sad, so depressing", she felt the tragedy "fractured" many of the off-screen bonds on the show.

She told the 'Therapuss with Jake Shane' podcast: "It was so unbelievable but I just had to keep going, I wasn't allowed to stop."

Asked if Cory's death had helped the cast "band together", she added: "No, I think it really fractured so much. I mean again, I can't speak for everyone, I think in some ways it did for certain people, but I think that ... for me it was so hard to I just completely broke."

Although she thanked the cast and particularly the crew for "holding [her] up so much", she added: "A lot of [the original cast] were gone by then which was hard."

Lea - who has two children, Every, four, and nine-month-old Emery, with husband Zandy Reich - has remained close to some of her former co-stars, including Dianna Agron and Darren Criss, and they will always be "family" to her.

She said: "To me it's like there is such a comfort because we all really did go through something that only we will ever understand, so it's just, I feel so safe with them and so comfortable -- family forever."

The actress has very clear memories of her time on the show and what was going on behind the scenes at the time.

Asked if there was anything happening backstage that she wished the people watching knew about, she said: "Literally everything … we were all so young and everybody was growing up and falling in love and for me that was a huge part of the whole experience for me ... was my, this great love.

"It was so unbelievable that you would be watching the show and when I watch it I can tell you exactly ... I'd be like 'Oh, that day I was sobbing in my dressing room.' Or, 'That day was the best day in the world' ... But the only people that know all of that were the people who were in that room."

Lea also teased that she may "write a book" one day about her "wild" experiences during the filming of 'Glee'.

She added: "The show means so much to me, the work that I did, and I love Rachel so much."