The Coronation Street actress recently hit back at several users who criticised her for not breastfeeding her daughter Polly.
Marsh explained that she was unable to produce "enough milk" to feed her prematurely born baby.
"Nobody has the right to question my dedication to my daughter and her well-being," she told new magazine. "I have done everything in my power to get this little girl here. If it hadn't been for the things I've done and the sacrifices I've made, she would not be here now. I didn't move from my house for three months. As far as not breastfeeding is concerned, I attempted it and it wasn't working out for her."
Marsh said of her two-week effort: "I used to sit for hours on end with a breast pump stuck to my boob and milk myself like Daisy the cow. I was getting up at 4am to do it, because they said that's when the baby would be waking up.
"Unfortunately, it's not second nature to all of us. If, for the baby's development, it's better to do what the hospital suggests, that¹s what I'm going to do. So they can go away with their small-minded bigotry. I can't bear it."
Admitting that she "used to cry to Jamie [Lomas]" about giving up, she continued: "So to say I didn't attempt to breastfeed, they're talking about something they know nothing about. They don¹t know what I went through. There's no reason they should know what I went through.
"But when you're slinging around slanderous remarks and comments saying I'm a bad mum and I don't deserve her because I didn't try, they don¹t know what they're talking about. How dare they go on to a site and call me those names and judge me when they know nothing about the situation?"
Marsh added: "I'm not going to have small-minded cowards that hide behind a computer question my dedication to my child. It's the most disgusting thing I've read."
Read the full story in this week's new magazine - out today.
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