The TV presenter has been singled out by some for her role in the BBC's coverage of the Diamond Jubilee last weekend.
"People who sit lazily and judge others will never grow. They'll never take a look at themselves or feel content. Shame so many do," Cotton said on Twitter.
"Grown men who slag me off in articles/online are huge bullies. I love my job and wouldnt be doing it if i wasnt any good at it. (sic)"
She added: "Im a postive person who believes in treating people kindly. I dont understnad the mentality of others who think differently. Good vibes and happiness all round."
When one Twitter user told Cotton that she was "pretty rubbish on the Pageant day" and urged her to "find a new career" if she could not see why, she responded: "Right this is what im talking about. YOU=bully. Take a look at yourself. I have been working nonstop for 15 years thank you."
Cotton continued: "Thanks for your nice tweets guys! I was bullied at school so there's no way im having it again as a grown woman.
"Im from a working class family and have worked hard to get to where i am today. Others will just sit and do nothing but judge.
"In my last few tweets i have not said people cant have an opinion. Opinions are one thing, out right bullying is another. VERY different"
The TV presenter and DJ was recently criticised by her BBC radio colleague Huey Morgan following her Gold Sony Radio Academy Award for 'Best Music Programme', though the Fun Lovin' Criminals star later apologised for his remarks.
Cotton has previously dismissed critics of her past work as "odd people" who are "bitter and angry", claiming that they are "famous for slagging people off".
She also revealed that she was bullied by older girls at school for her early TV career in The Disney Club and Diggit.
