My mum left school at 14 with nothing - she's about to retire after working her way into and up a very male-dominated profession, where she is currently ranked 7th in the entire country.
I did do GCSEs and A'levels, but dropped out of Uni three times. My area at work covers Europe, Middle East and Africa in a very techy field.
This really isn't to boast; it's to demonstrate that the right person, given the right chances, with the right....desires, I guess, can never be held back 
It is entirely possible for you to go to college, get the standard 5 GCSEs, do an ICT course because you need IT skills just as much as you need writing skills, start getting some temping jobs and begin working your way into a career. It's how it happened for me. I got extremely lucky - I temped, was a data monkey, got a job in a library, got another job that moved me up a tiny bit, and on and on until I'm where I am now. I also thought, I've got and not done much. I have no experience. Temping the first few times was terrifying - I had no experience of office etiquette, I couldn't type a zillion words a minute, I had no idea what I was doing....but somehow it all just sort of fell into place.
Really - get the ICT skills. If you want to work in an office, temping is a great way to get exeprience. But the temp companies will probably test you in Word, Excel, PowerPoint etc. Do the ICT alongside the GCSEs. You can do it, you really can, if you WANT to 