I want to join the British Army and be in the infantry, but at the same time I don't want to?

Hey mate, I was in the same boat as you about four years ago, I wanted to do Animal care, but I didn't have the GCSE to do so. So I went and talk to college, and they told me that most college will allow you to work towards GCSE while doing your normal lessons.
So have you spoken to your college about this, you be surprise how many people go to college without any grades at all. I got a friend who went and did media studies and he had no qualifications at all, and now he is a level 3 student.

Now the army. Myself I am going to join once I finished my last year of college. So see if you can do the course and work towards your grades, than have a think about joining.