woah, 3/4 during year 10 - nice!
Yeah in my experience Chinese SL was kind of a depressing subject. I think it's because of the way the Chinese language schools run the show over here and make it basically the worst thing ever.
I think an important part of doing well in sl is preparing super early. Like, try to have your general convo and detailed study done soon, and start memorising and rehearsing soon as well. For essays and translation, try to get a lot of practice and a lot of feedback. You have to kind of accept that the essays in chinese sl are just super rigid in their structure, which is is both a plus and a minus - a plus because that makes them predictable and easy to prepare for, and a minus because it makes them incredibly bland to write (unless you choose the creative essay like an absolute mad lad).
Basically you have to do what you already know you have to do - bite the bullet, endure, and work hard. You can chill out a little with your 1/2s - prioritise the 3/4.
Anyways, as someone who also had no motivation for Chinese, I assure you that there is light at the end of the tunnel, and that you'll be thankful that you did it once it's all over. Regardless of study score, learning Chinese is incredibly valuable, and I'd argue somewhat important for someone with a Chinese background.
Good luck!