I think you need to find some sort of direction in your life rather than change course and hope for the best. To me you have a few options:
- You give yourself a kick up the bum and knuckle down on your current subjects with a view of getting half decent grades
- You switch to something else but in reality are likely to be equally unmotivated. The fact that you are suggesting you might study geography or history or something suggests you are clutching at straws.
- You get out of education, give yourself a break and get a job and a bit of life experience.
However, whatever you do do, don't jump from your current pathway until the alternative is secured.
Good luck!