I am a Steam user, I did not receive an email. If you are a Steam user I would recommend using the two-step verification process they have. It uses a password

I am a Steam user, I did not receive an email. If you are a Steam user I would recommend using the two-step verification process they have. It uses a password sent to your email to verify you when logging in using a new computer. Hopefully you're Steam and associated email passwords are not the same. This is, of course, no replacement to changing your password - you should definitely do that - but allows us to relax a bit in case something similar happens again.