Hey
Insanebrech
Unfortunately, the claims of double XP for OSRS are a scam, and the stream you found it on would have directed you to a phishing website, designed to look like the real website but it is actually a fake. Once they got your details, they were able to login and steal your items/gold
If the stream is still up, you can report it to Twitch and they will hopefully take it down. If you still have the phishing website, you can email
with the info and they will be able to investigate it
To secure your account, computer & email from further hijackings, there's a step by step guide
here
which explains the best methods to use
If you need any further help regarding your account, I would recommend posting in the
Community Led Account Help
section
Regarding upcoming events on OSRS, always check the official homepage to see what's on the horizon - Big news is always posted there so you can crosscheck if the information you've seen/heard about is accurate or not
I hope that sheds some light on what happened and how to avoid it again