iPhone 5s crashed and is not responding
I bought my iPhone 5S back in July 2014 but lately it's been acting weird, like I've had apps like Spotify suddenly crash and I'll be unable to launch the app until I restart my phone. There was once where my phone 'died' even though it still had battery and I was unable to restart it until a couple minutes later. About half an hour ago, my phone suddenly crashed and automatically 'restarted' itself. However, it is currently unresponsive and is stuck on the white background and black apple logo thing that appears when you switch on an iPhone. It has been this way for about half an hour. I've tried charging it but that doesn't work (it didn't make the usual vibrations that happen when you charge it), it can't connect to iTunes and it also doesn't respond to the home or lock buttons. I honestly don't know what to do and would like to know if anyone has experienced this before or has any advice on what I should do. Thanks
iPhone 5s, iOS 8.3