scam emails sent from phone

I've been having a problem & I haven't been able to find any info about.

In my email "Junk" box, I saw two emails that were obviously scams from the email titles. Without opening either one, I clicked on the box next to both emails and went to click on "block" at which point my email told me I could not "block my own email address." Confused, I opened the emails and they were sent from me to me, but I knew I hadn't sent them as they were both scam emails. I changed my email password, but they appear to have come from/been sent from my iphone to my email inbox. I have also changed my phone's password. Is there anything else I should do? Can anyone tell me what is going on/happened? Thanks.