there is a common misconception that needs clarification here,
what is happening is that your account is being cloned, not hacked
being hacked means they are INSIDE your account and can access all your info,
being cloned means they steal a picture, create a fake account ( that is not tied to , or affiliated with, your account.
The purpose is to garner your friend list by sending them invites, and then innundate them with some form of spam.
so your account was not hacked, it was cloned, your information has not been compromised in your account any more than people seeing what you post is
also, texting, and messenger on facebook are totally seperate,messenger can do just like your browser does, and it triggers what pages you look at with cookies so they can tailor the ads you see to match yoru interest, its how web sites, and facebook pay for their existance, no I dont like it either, but its a reality.