Email sending links to Facebook friends?

[Lacey]

I got a message from a friend on Facebook saying that she got an email (yahoo account) from me containing a link. My email is set to "ONLY ME" on Facebook so none of my friends have it. She's not even on my contacts list on my yahoo account so I don't understand how she got an email sent to HER email from MINE. I do not have her email address and she does not have mine. I checked my sent box on yahoo and there are no unusual activities of someone else sending from my account. Has anyone else had this issue? Is it possible to fix? If so, how? Thank you!
** My friend just told me that she didn't receive an email from MY email address..that it was djs2006 as the "email" she received. So they just used my name? This whole situation is just really weird!

[Kittysue]

Run a full virus scan, then download and run Malwarebytes. After running both scans, delete your browsing history and cookies and empty your cache then restart your computer
Also delete any apps you don't use on Facebook. If you read the fine print on most apps, it will say that by downloading it you are allowing them to access your information and all of your Friends' information.