Why is my iphone playing up? - 1

For the last 6 moths I've had the iPhone 6. Today I woke up to find that on my call button, I could only dial people and my contact list had vanished so now I have no contacts on my phone and I can't add anyone either. Then I get a text come though but the name is gone so i don't know who that s off either and another thing that has happened today is that my phone will not detect my camera. I go onto apps such as snapchat, instagram, whatsapp etc. And it says turn on camera for this app. The usual steps come onto my screen, i go to setting press accept and then my camera should be working but no, it won't work at all. I get about 2 days of 3g when i pay for unlimited ( by the way i'm on EE) and most of the time when i go onto an app the screen will freeze and the next thing you know, its gone off an i'm back at home screen.Sometimes my music playlist will disappear for days and then reaper the next. Is this a problem with my actual iPhone or has anyone else had similar things?

Iphone playing up