The pair fell out earlier this month after she posted a photograph of the two together with a comment, sparking a Twitter war of words.
Fowler later apologised for using the phrase "half-breed" but maintained that she was not aware that the word had any racist connotations.
Discussing the incident with Heat, she has now said: "He was shouting at me, all sweaty and up in my face. 'Why are you calling me 'big time' on Twitter? Why are you f**king saying that?'.
"I was scared, it was intimidating. I think he'd been drinking. Then he said, 'I don't know who you are, you're nobody, you've got fake hair, fake t*ts and fake teeth. You look like a f**king horse'.
"It doesn't matter who I am, he shouldn't be rude to anyone who asks for a picture."
Of Collins's claims that she exhibited homophobia and possibly racism, she added: "He didn't claim anything like that to my face. And I was with three gay guys that night
"I feel like suing him, because I'm not racist or homophobic. Marcus is the rudest person I've ever met and he's an idiot.
"It seems like fame has gone to his head. He's from a reality show as well, and at least I was on three series of mine."