The reality show winner believes that her connection with the former EastEnders actress was instant and their friendship will last outside the house.
She told the Celebrity Big Brother website: "Natalie and I never knew each other except having met each other on Loose Women. Once she left, the soul went out of it for me.
"I felt lonely in the last week, because when Natalie left I lost my circle of friends."
Addressing her foul-mouthed clash with Michael Madsen on Bit on the Side, the star said: "Michael upset me because I thought that he would take it in good spirits and, he may have nipped my bum, I thought it was ungracious of him to be like he was [during my interview]."
Of her victory, Welch added: "I don't think that anyone thinks about winning. In the last week, all I wanted to do is get out. I just wanted to get out. The last week was the hardest for me.
"When you win you've got the public vote, but that doesn't mean you've got the housemate vote, so my paranoia is, 'Oh my God, what are they thinking?'
"It's the most flattering and bizarre thing that has ever happened in my life. I've always said over the years, 'You'll never catch me on this show'."
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