Should I go on long term sick leave? Everyone else is

I work for a major investment finance firm, we have a bunch of clients. For the last year they've got me "hitting the ground running" with no onboarding, out of date if any SOPs, and no training. Also they want me to hit new quality control targets. New as the managers only just learned we were required to hit any financial quality control targets at all.

This week I gave up. Teams messages, zoom messages (for our team in SA), inbound calls from clients, financial advisors, and call handlers who won't read case notes, e-mails from a plethora of stakeholders, constant degradation from quality personnel, HR needing random forms urgently because of new company policies - I didn't bother with any assigned tasks because the only thing to do was to sit there and get fucked all day.

If I don't reply within 10 seconds they'll escalate. This would usually go to my team, except most of them are on long term sick from stress. This week alone out of a team of 6, I was only one working because the rest were off sick from stress. So if I don't do something urgent it goes to some bigwig who e-mails me demanding immediate action and copies in lots of far up people.

There's a lot of good things about the company, I've made some allies here who'd be furious to see me leave (primarily because I actually work well and don't refuse tasks) but the job is so incredibly stressful. Since there is no knowledgebase because the company thinks it's cheaper to not maintain one, and everyone is on sick from stress, trying to work out basic tasks is the most miserable job in the world.

What do you think? Time to get in the sick leave action? Everyone else has! And standard painkillers aren't helping with my headaches anymore.