iphone 5s won't download apps or music

[Rachloo]

Hi, I know this is a iPhone problem but you guys helped so much before that I thought it was worth asking. All of a sudden my iPhone won't download apps anymore or music. My apple id is correct, i've installed the new update to see if that would fix it. I've reset my network settings and done a proper power down reset (turning it off and holding down the home button) and still every time I click on and app it says 'get', then 'install' and then goes back to 'get' again! infuriating! It then says 'cannot connect to iTunes'.

Please help I really need to download an app for my new fitness tracker.

Thank you!!!