Major issue.

Hi,so I was texting a friend on my N4 and suddenly my phone deleted all my contacts all text messages all the call log and all calendar events.It also shut down but before it shut down I couldn't receive texts from anybody and it had no signal even though a minute ago i had full bars. and I was wondering how did this happen and what exactly happened to it?

 

Nope. all my apps were still there. and all my widgets and my gmail accounts were all there.