Should I consider medicine?

I am in year 11 now and I am about to take my gcse's and move onto a-levels. This means that whether i become a doctor or not will affect my choices. I am between taking maths, spanish biology and history and then going onto study politics and go into policy, or taking chemisrty instead of history and doing medicine. I am good at science and am predicted a*'s and always thought that i would do chemistry and a-level and i do enjoy it, but i also really like history and i am very interested in current affairs. I really want to help people and make a difference in my life but also want to do a career i like. Can someone tell me what being a doctor involves and the highs and the lows, as well as any advice on what i should do?