Are you passionate about gaming? Is it something you think about even when you're not doing it? Can you see yourself doing this for the rest of your life, even if it means long work weeks and a lot of stress? Are you willing to work damn hard for what you want?
If so, then you should be in a video game related career. But the key is to set yourself up for what best suits you.
Your marks in English aren't so hot, but it depends on what your English classes actually entail. Do you have trouble writing? Do you dislike writing? Difficulties can be overcome, but if you don't like to write, you won't like to be a games journalist. Yes you'll get to play games before the public does, but most of your job is going to be writing. You need to be sure that you can commit yourself to 40 hours a week of writing. (Not saying you'll be writing all day every day, but it's going to be a large part of your job)
Poor marks can be overcome. I barely graduated high school due to slacking off and now I've been a Dean's List student at my college for the past fourteen months and have maintained a 4.0. In addition to that, I got a job working on a high-profile studio mod team that's going places quickly, so I'm setting myself up for an excellent career. So trust me, marks in high school can be overcome.
So the first thing you need to do is decide if writing is really something you love to do. If it is, then I suggest Googling online game sites or zines and seeing if they have any job openings for writers. You can get a taste of what it's like to be on a team and you can also rack up some credits for your portfolio and resume which you can then present to paying employers once you're out of high school.
Best of luck.