"Cannot Connect to iTunes Store, App Store" etc.

I have come across a problem on my iPhone; A few days ago it stopped receiving emails on my phone and I noticed that I could not connect to the iTunes Store, the App store, iMessage or even my Bandcamp and Whatsapp Apps.

I went to a friend's house and tried their WiFi to see if this was the problem. Bandcamp and Whatsapp and even my email account were working fine again, but anything connected to my AppleID seems to still not be working at all.

And when attempting to sign into my Apple ID via the "iTunes & App stores" section of the "Settings" I receive the Alert "Verification Failed" "There was an error connecting to the Apple ID server. Any Tips? I have an iPhone 6 with no sim. Thank You.

P.s. Upon returning to my home the Bandcamp, Whatsapp and email stopped working all over again. What could be the problem here as well?