HTC stuck in boot

[japsara1]

Hi. I have a HTC one m8 which is stuck in boot. It happened a little after downloading the latest os updates and started with my phone crashing every time I turned my phone camera to landscape. Contacted HTC and tried to reset but cannot get past boot screen. Concerned that the OS has been wiped and my laptop won't recognise the phone when I plug it in. On HBOOT screen it says Locked S ON which seems in itself to hinder my chances of trying to flash or use ADB. But please, if anyone has any suggestions I'd be really grateful. Thanks