AoA,
Brother, if you intend to opt int'l law than must select int'l relations as course of the former relates with the later. And don't worry, I myself couldn't get through in my maiden attempt last year. I examined the reasons and the most basic reason of my failure is lack of hard work and practice. Stay in touch with a good English teacher who could evaluate your stuff. Rest subjects are comparatively easy to cover but essay always gives hard time. Crack it through daily practice.
Action speaks louder than words. Just work hard and let your success beat the drums. Good luck.
Stay blessed. Remember in prayers.
Regards,
RMKamran.