Year 13 - on Ds - is it too late

I’ve seen it happen, so yes! But you’re gonna need to step up your game. I’d recommend spending a bit of time (a day or two) going through your syllabus and figuring out what you struggle most with in your subjects. Then focus your initial revision and work on those topics. When you’re closer to exam season do the same thing again and focus on those few topics you still don’t get high marks on. This strategy should give you the knowledge you need to get your grades.
Good luck! You got this

Thank you.
Do you think it’s okay to miss some content out with that strategy

Yes, but ofc it would be better not to. Many students don’t manage to completely revise the entirely of the syllabus anyway.
The most important thing is that you get the big concepts down - the ones that are costing you the most marks. If you miss some small content that you kind of know that’s not the end of the world. However, I didn’t do economics or politics so I have no idea what the structure of your exams are. But that’s also why I’m talking about focusing on what’s costing you marks, bc that’s what’s going to be the most important part in determining your grade. If you know all those important topics that will definitely come up in the exams well (even if you’re still a bit shaky on some of the smaller topics) that should still get you through.
Sorry bit of a mess of a paragraph there - let me know if you don’t understand anything!