My Nexus 5 is unresponsive can anyone help?

[seasickseagull#CB]

I have Lollipop 5.1.1 installed on my Nexus 5. I was responding to an SMS message and my Nexus 5 froze. The only thing it will do is turn the screen on or off when I press the power button. I took the SIM card out and then put it back in again..but still the same. I connected my Nexus % to my laptop, and the laptop reognized the Nexus 5 but no files where shown. Can anyone plesase help me. Thank you

 

[B. Diddy]

Welcome to Android Central! When you turn the screen on, what shows up? Is it frozen on some app screen? Or is the screen lighting up but it's just blank?