Adding an alias emptied by entire account!!!

I've just added a new alias email address but kept my original email address as the primary address. Outlook then refreshed by account clearing thousands of emails out, losing all my contacts. It's literally a brand new blank account and my old one seems to be totally gone. There was no warning whatsoever that this might happen, I thought I was just adding an extra address to send/receive from. I've deleted the alias account but it made no difference. PLEASE help me I'm in big trouble if i've just lost all my contacts and emails!!!