iPhone 6 most likely hacked. Please help.

I know everybody says its "impossible" for an iPhone to be hacked if it's not jail broken or in the possession of the hacker, but too many concerning things have been happening lately to lead me to believe it's hacked. No, it is not jail broken and no it has not been in the possession of anybody. Not only is my battery draining crazy fast, but this person who I suspect is doing the hacking I have heard talking about something I never said to anybody out loud, and has been posting things on social media that directly correlate with the exact thing I was very previously just talking to my friends about either over text or Skype. If it happened once, or twice, okay, maybe a coincidence. But this has happened far too many times in such close time proximity that it cannot be a coincidence. My friends absolutely hate this person I suspect is doing this, so I know they're not telling them anything.

I frequently check my iCloud to see what devices are signed in, and it's always just my iPhone, so I know it's not my iCloud that's hacked. I also frequently change my passwords and have Lookout Security on my phone. It really baffles me, and scares me.

If there is any possible way I could find out for sure if somebody is spying on my phone, please let me know.