I would recommend you to take Science stream, even though you think journalism has nothing to do with it. When I was your age, (I sound so old here but I'm actually only an SPM student) I knew for sure which stream I wanted to go to because at that time I aspired to be a psychologist so it was only logical that I take science stream. Now, after realising that there is an influx of medical students in Malaysia and also taking into account the poor job prospects of a psychologist here, my ambition has shifted from that of a psychologist to an accountant. A huge turnaround, I know. But had I known then that I wanted to be an accountant, I would still have chosen to be in the science stream.

Being in the science stream of my school has taught me a lot of things. I do not regret learning Physics, Chemistry, Biology or even the infamous Add. Maths even though I struggled learning these subjects at first. I also took Accounting as an extra subject for the lulz because I wanted that extra A+ for potential scholarships. But thankfully, after much hard work and effort, I overcame the difficulties I faced at the start. What I'm trying to say here is that with a fair amount of hard work and some commitment here and there, being in the science stream is not actually as stressful as you think it is. And also, why do you think the art stream would be more suited for the field of journalism? You still have to learn Science, Basic Economy, Art, Accounting, Business and the likes which doesn't really have much to do with journalism as well.

However, I do also believe it doesn't matter which stream one is it. As long as you are conscientious in what you do and hardworking enough, nothing will be too big of a challenge for you to surmount.

TL;DR : I would suggest that you enter the science stream even though you think journalism has nothing to do with it. Your ambition may change in the future. Moreover, it opens up your eyes, learning the science subjects. And it is also not as stressful as you think it is.

Always glad to be of some help. Nothing is impossible if you work hard enough and are willing to make some small sacrifices in the long run. And thanks! Hope that you will be able to make a decision which suits you best.