People have put me off my ULTIMATE dream!!?

It is my ultimate dream to write for a glossy magazine such as Glamour. I have wanted to be a journalist for a while and would also love to work for the BBC. However, people have said to me how difficult this is and it's starting to put me off. I mean, I'm only 16 but I already have some published articles and a portfolio. If I could choose, I would write for a fashion magazine. Just think, how many other 1000's of girls want to as well. I don't know what to think. Thanks x