iMessage won t activate iCloud Mail won t sync Phone doesn t show iPhone

Okay, so I've had a weird array of problems the past few days, and I'd have to think they are related. Here is what has been going on:

-I noticed iMessage wasn't working anymore (just sending as normal SMS) so I attempted to turn it on, and everytime it says: "Activation Unsuccessful. Turn on iMessage to try again." I've tried again, it doesn't work.

-All of a sudden my iCloud mail account isn't syncing correctly. On my computer I am constantly prompted to enter the password as it rejected my old one.

-Twitter alerted me today with a popup that said PUSH notifcations weren't enabled, and I needed to connect to iTunes to fix it.

-When I plug my iPhone into my computer, on the summary page of the device next to Phone Number it just says "n/a"

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I've searched all over and scoured the forums and found a bunch of 'solutions' that I've tried, none of them have work. Here is what I've tried so far to try to remedy:

-Restarting iPhone

-Resetting iPhone

-Connecting/Disconnecting to WiFi

-Set WiFi DNS to 8.8.8.8

-Plugging into computer and syncing with iTunes

-Changed iCloud password & re-entered information for all accounts (mail, icloud, imessage)

Any help is greatly appreciated, and I'm open to trying any suggestions you may have!

Thanks!