Terrible thing to happen. In addition to what Tuxas said follow these rules:
If someone sends you a pic and you don't know who the sender is NEVER open it. If for some reason you feel the need to, do so when you are alone. Sorry to hear you learned that lesson the hard way.
If someone sends you something offensive, report, delete, and block communication so that they can't get to you again.
Post provided "as is" and confers no rights.
You're special...just like everyone else.