Permanent lag not so long ago

Hi guys, i have a big problem. Playin' like a year ago or so here on Lorda. All was fine about everything until Feb 9.
On wednesday evening i had a raid with guild, normally i have 70ms just as on this day. Then suddenly went up to 300, i had to leave group, i cant play at all from that day cuz i have like 2-3 sec delay on everything, ppl teleporting around me etc. I was hoping this will end by itself but nah.
At the very evening/morning it seems fine for some hours when pop is lower.

My brother has the same isssue. We're on the same internet in same house. Both of us has normal latency in any other game.

Any ideas what can be the problem? This delay makes the game unplayable.