Politics and history isn't a weird combination at all - I know loads of people who do both. I'm not so sure about politics, but History is very intensive and there is a lot to remember. Out of all the subjects I do I would say History is the worst in terms of workload (I do Maths, French, English Lit as well). However if you are enjoying GCSE and are interested in the subject I would definitely recommend doing it. As for the syllabus, I'm doing Modern Britain and Russia as opposed to Tudors and the Cold War, so I can't be of much help there. I'm personally finding my syllabus very interesting. I can say though that my friends at my old school that are doing History are also doing Tudors and the Cold War, and I haven't heard any complaints about the syllabus being boring or anything.
Biology I would definitely say to steer clear of as at A-Level it's renowned for how heavy it is in terms of content. It'd definitely be a drag to go through if you don't like it.
However also keep in mind that with History and Politics there are a lot of essays, obviously. You've said you don't particularly like writing essays so maybe think about that as well when making your choices.
Good luck!