Lost ALL my email

Hello all, I seemed to have been automatically switched to the new outlook interface for emails and with the switch i have Lost ALL of my emails!
NB

• I did not manually choose the new interface
• I did not create any aliases
• My account have not been hacked
• I only use my browser on my computer to view emails. No other devices.

Can someone from Microsoft PLEASE ASSIST!! i have lost YEARS of emails. I dont see how this could be acceptable service from microsoft!!!