IMessage on iPhone is being weird?

When I first got my iPhone 4S I set up my iPhone iMessage with MY phone number, not an account.well today my sister sent me a text through I message and someone replied saying "who are you?" it wasn't me that sent the text! Then when I was in the middle of sending my sister a text it shows up that the person who's using my iMessage replied "I'm serious " to my sister. I saw it happen.what's going on am I being hacked? I turned my iMessage off until I know what's going on

Sounds like you might have sent a group message and someone in the group is replying?

  • Is my iMessage set up weird? So I can text and Receive texts from numbers that are not with iMessage without Wi-Fi or cellular data, but I never Receive or never could send messages to my two friends who have iPhones with iMessage or my sister who has an iPod with iMessage. I need either Wi-Fi or cellular data to do so. Why is this? Can I fix this?
  • Is it weird that I was born in 1996 and I can't relate to being Generation Z? I was born in 1996 and I can't relate to those born after 1999 because I wasn't as spoiled as those born in the 2000s. I'm aware that there was internet in the mid to late 90s but the internet was not really used as much until say 2000. Like a good example is that a 5 year old today is on an IPhone at age 5 when they should be enjoying their childhood. I guess I call us 1996-1999 babies as hybrids while those born after 1999 are true Gen Z
  • IPhone storage is being weird? When I go into my settings, it says that I have 174 GB available on iCloud. But when I try to download something on my iPhone, it says that I don't have enough available storage. Why is it doing this and how do I fix the problem so that I can download stuff again?
  • IPhone being weird, how to reset? Yesterday I wanted to update my iPhone so I did it without connecting it to iTunes. Since then it has been showing the Apple logo in front of a black background, then the screen goes completely black and just repeats. I tried to hold down the home and power but nothing happened. When I try to connect it to my laptop it doesn't show up in iTunes. Does anyone know what I should do? I have all my stuff backed up so I'm willing to reset it to factory settings.