EastEnders star Samantha Womack said her return to soap as Ronnie Mitchell is "unfinished business".
The actress quit the BBC1 soap after featuring in a controversial storyline where Ronnie abducted Kat Slater's baby and replaced him with her own son, who had died.
She told Hello! magazine: "It was a brilliant plot line but very difficult to play.
"It was draining emotionally and physically and by the end I was shattered with all the crying and weeping."
The 40-year-old mother of two said: "It all started to feel like it was unfinished business. I even got a bit jealous not seeing her on screen. I've really missed the cast too. They're like my extended family so it feels like your first day at school.
"Ronnie was a broken bird at the end but after serving time in prison she'll be steely and a bit of a matriarch with a lot more power and backbone. She's found her old inner strength. A bit like me."
She told the magazine how she dealt with her grief after her father committed suicide saying: "Dad was 60 when he took his own life. It's very hard to be the child of someone who does that."