Can't access icloud following changing email address
I have had to change my email address for my apple id. I have updated this in iTunes and icloud on my pc and i have updated my iTunes on my phone and ipad but it won't let me change the icloud address to my new one. in the end I have had to turn it off on the ipad and now it won't let me set icloud back up on my ipad with my new email address, it is greyed out. Please can someone help me.
iPad Mini, iOS 8