How do you deal with current metagame bullshit?

I haven't played competitive in about 8 months, and I decided to check out Showdown. Much to my dismay, the metagame is fucking ridiculous. I used to sit comfortably around 1400-1500 with a baton pass team, but apparently baton pass teams are now banned for some reason, and I'm having a lot of trouble coping with muh priority everything, le knock-off bonanza, and all the other bullshit that came with this new generation.

So as someone who's more familiar with last gen's/the early stages of 6th gen's metagame, what changes do I need to be aware of, and which threats/moves/irritants should I be preparing for?