I've been getting this error extremely frequently, too.

I started playing about 11 days ago and, for the first week, it's worked fine. But for the last 4 days it's been kicking me out within 5 minutes of logging in and, when I do manage to play within that 5 minutes, it's extremely laggy.
Sometimes, on the night of a blue moon when the planets align, I can play it for maybe 2 hours (give or take) problem free until it kicks in again and starts giving me 90002. I'm not particularly knowledgeable on things like routers, ISP etc, but I've tried resetting my router, turning it on/off, and restarting my PS4 but nothing's worked. I can't even try going wired because that's not an option right now. I can play every single one of my other games as smooth as hell, but not this one.
This is particularly annoying because this game is subscription based, so every day that this plagues me, I'm effectively losing my money and interest in the game which SUCKS, because I really like it...
If this carries on I'll probably end up having to cancel my subscription until it gets sorted. I don't see why it would work fine the first week and act like shit for the rest.