exchange email password doesnt work after update

I upgraded to 15.1 last night and now my email account that is set up in microsoft exchange no longer works on my iphone. I have the same email account on my ipad and it does work after I upgraded. I kept being asked to reinput my email account password which I did many times but it would not accept it as valid. I signed into the account using safari and it worked fine. Therefore, it has to be something that happened in the upgrade....I was using it on my phone up until I upgraded.