I had signed ma mobile number and then deleted. now unable to log into my messenger using that ID .plz help?

I had signed into a mobile number and then followed "Click the Messenger menu and select Preferences.Click the "General" category.Click the "Edit mobile device" on and enter your Yahoo! ID and pword to sign in to Yahoo! Mobile.Under the Other Mobile Devices section, click the trashcan icon to the right of the device.Click Delete." an deleted ma mobile number from yahoo.... now am unable to log in to my id..... I have this ID since 2003 ...cannot afford to lose it.... am helpless ....plz help me....plz ...