Problem setting up two users on one MBP

I have had a 13" MBP/Retina for about a year. Works fine without issues until both my wife and I purchased iPhones. Then we had two Apple IDs, two contact lists, and messages going everywhere. And issues backing up to our Apple ID accounts. I have tried many configurations to resolve these conflicts with varying degrees of failure. My last attempt was to establish 2 separate user accounts on the login page. When each one was opened it was set up to log into icloud with the unique user ID. It worked fine as long as only one account was logged in and the email was not set up. If you logged into User 1and then switched user to User2 the chaos ensued. and if you wanted each user to be able to gather the email from their unique account and a common account it went bonkers.

What is the best way to resolve this dilemma ?