my iphone has been stolen and i need help

Hello,

my iPhone has been stolen two days ago. Unfortunately, I was not able to activate Find My iPhone in time and the thief was able to hack my device. He got hold of my Gmail account and changed the password along with the associated phone number. The worst part is I was so nervous I removed the stolen device from Find My iPhone by mistake(!!) so I have no way of knowing what's going on with it anymore. The device has all my information on it including passwords, credit cards, id & passport, photos, etc. This person already logged in to my facebook account form he's mac laptop and I feel like he can really harm me. The stolen phone is still connected to my iCloud account, is there any way to delete it from afar?

PLEASE HELP ME!!