If it isn't your Internet service then it may very well be Cloudflare. I know the Cloudflare thing happened a few days ago and it was down for a lot of people, disabling them from connecting. Some areas had it back up faster than others but I think a few areas might still be down maybe including yours like Hakumi mentioned, which there's no way to fix that except wait.
If you were playing a month ago then you're familiar with the new login system I'd assume, other than the difficulty of keeping the tab logged in, as it was introduced some time back in December I think.
