The former Coronation Street star and singer appeared on the BBC show, which she usually presents with Gethin Jones, on Friday (1 October).
During the interview, she explained that her father being diagnosed with prostate cancer in March had led to her seeking mental health treatment.
"I think it’s fair to say that the last few months have been ridiculously busy with one thing and another for me and my family,” Marsh said.
"Starting at the beginning of the year when I had my double hernia op, which should have been much more straightforward than it was, and then we found out that my dad has cancer, and then we caught Covid.”
Describing it as a “terrifying time”, she continued: “I’ve been off obviously for the last few weeks. And one of the reasons for that is that I want to be here for my dad, I need to be here to support my family. And it was absolutely the right choice to make.
“I’ve been able to be around, I’ve been able to be there when they’ve needed me to visit more. And spend time with them really, and just kind of help them coming to terms with everything.
"All we can do is just be there for him, support mum, and help them through what is one of the most difficult times of their lives.”
Marsh went on to say that while her father’s health was improving, she’d brought her forthcoming wedding forward so that he could “walk me down the aisle”.
Access unlimited streaming of movies and TV shows with Amazon Prime Video Sign up now for a 30-day free trialSign up
She also said that his diagnosis had brought back panic attacks, which she had previously struggled with.
“For now I’m just going to take each day as it comes and not put any pressure on myself, so I’ll check in on the Morning Live family with my own family for now,” she said.
Additional reporting by Press Association
If you are experiencing feelings of distress and isolation, or are struggling to cope, The Samaritans offers support; you can speak to someone for free over the phone, in confidence, on 116 123 (UK and ROI), email email@example.com, or visit the Samaritans website to find details of your nearest branch.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies