seems like a website gain access to my account and start sending messages to my friends

[Linkhunter]

doesn't seem anywhere on steam how to option unlink I changed my password I don't know that going to help I look in steam support and I can't see any guide on that

[Supafly]

Scan for Malware/virus https://www.malwarebytes.com/mwb-download/
Deauthorize all devices https://store.steampowered.com/twofactor/manage
Change your Account password on a secure device, mobile phone for example.
Generate new back up codes https://store.steampowered.com/twofactor/manage
Revoke the API key https://steamcommunity.com/dev/apikey

Stop using dodgy sites

[Linkhunter]

thank you I was running on autopilot I do not think about the consequences