Switched to https...

You need to check how many google indexed pages are there with https...i think this will come back to normal once all urls are indexed with https...second thing is you need to add your https version in google search console and set https as the preferred url.

Traffic / rankings dropping after switching to SSL is quite common, just like any other redirection, Google takes time to get everything in order. Just make sure there are no errors in your SSL installation or in your redirections, and your traffic should be back to normal shortly.

I wouldn't panic if I were you.

This is very normal with switching to SSL.

Give it time and breathe deeply.