The actress's character Kirsty Soames has been subjecting fiancé Tyrone Dobbs (Alan Halsall) to beatings over the past few months, and her attacks are only set to get worse in upcoming episodes.
Gumede told itv.com of the scenes: "The level of violence with Kirsty has escalated to a really dangerous point now. Her sense of reality is starting to become quite warped, I think.
"I think the story is really taking quite a dark turn. It's been very uncomfortable to film - worthwhile, I think we're telling a great story - but it's becoming quite harrowing to be a part of."
Tonight's (November 26) Coronation Street episode sees Kirsty give Tyrone his worst beating yet after he rebukes her for confiscating his mobile phone and keys.
Gumede explained: "It's extremely brutal and it was really difficult to film, but hopefully it will look realistic. I would watch from behind a cushion or a sofa or something, or through fingers!"
Reports have already revealed that Tyrone will plot against his unstable partner by setting a date for their wedding, seeing marriage as a way to finally secure parental responsibility of his daughter Ruby after Kirsty left him off the birth certificate. He would then be able to dump Kirsty without losing custody of the baby.
However, Gumede warned that Tyrone may be playing with fire by hatching the desperate plan.
She said: "The next part of the story will be, 'Will they make it down the aisle?' If Kirsty finds out what's going on behind her back, there could be even bigger consequences than there already have been. So who knows what's going to happen to Tyrone?"
Coronation Street continues tonight (November 26) at 7.30pm on ITV1.