IPhone 5 has been acting strange, could it have been hacked?

Okay so I have an IPhone 5 and it goes through stages where the battery acts funky. It will say I have 90% battery and the go down to 40% and just chill there for awhile. Or sometimes it will be at like 45% battery (or less sometimes) and just shut off out of no where and won't turn back on because it's "dead". Then I will put it on the charger and it will start back up again with like 50% battery all of the sudden. I have not updated to IOS 7 yet. Still have the old one going so maybe that has something do with it?
Also, I sent my mom a text message and it sent to her wrong. It was a kind of long message, so maybe that's why? Instead of what I actually wrote, at the end it sent "He just needs to keep his mouth shut!" Which isn't even close to what I wrote. I've also got a few texts from weird numbers so I'm kind of nervous. I check my bank and stuff on my phone, don't want it hacked. Thoughts and solutions would be appreciated!

Turn off push technology and it will improve your battery life

  • My iPhone 6 has been acting a bit weird lately? I'll be texting a few people on imessaging or kik, and I'll have to double tap the home button. Sometimes when I double tap, it brings me to what looks like my home screen, but with no apps, just the wallpaper I have set. When I press the home button again, nothing happens. I have to restart my phone. This can happen up to 3,4, or even 5 times a day. What does this mean? Is something wrong with my iPhone? I have the newest updates installed btw.
  • My iphone is acting strange? So whenever i open up the safari app, it starts to open and then immediately closes. And it has done this with apps too, and some apps won't load at all.also, it keeps saying its low on storage and to increase the storage.could this be why it's acting strange? And in the safari app, videos won't play. And my mail is not loading properly at all either.
  • My iphone is acting quite strange? I have a Iphone 4s right? Well when I go to my music and tap on one song, I get a different one than I wanted. Why is this happening? Its kind of making me mad. I'm ready to throw my phone against the wall. I wanted to figure out what's going on before I hastily do something I'm going to regret.
  • My iPhone has been acting weird For the past few weeks, whenever I hit the middle button to escape an app I'm in, it often doesn't work, and I have to hit it a few times before I can get out of the app. I tried deleting some apps, to see if it would help, but even with a lot less apps on my phone, it didn't help anything. Does anyone know why this is happening and/or how I can get it working better again?