SSD Disappearing on my Alienware 17 R3

I have an Alienware 17 R3 with the 256gb ssd (I gather a Samsung PM951) and a 1tb HDD. The ssd is the boot drive. I have an additional m.2 ssd (an SM951) which holds most of my games, but that is not part of this problem. It is only the PM951 that shipped with the laptop.

I have had the laptop for around 18 months and use it on and off (usually spells of a few days every month or two - sadly life gets in the way a lot) usually for gaming and browsing.

Weirdly, ever since the warranty expired earlier this year the laptop has started acting strangely (it literally started awithin a day or two of the expiry). Games would stutter, the system slowed down. All very strange. Then recently I tried to reset the system in the hope it was a buildup of files, only to find that the windows recovery drive installed windows onto the HDD (deleting all my data of course). Not happy after that.

To get to the point, the saga continued yesterday when I kept getting BSODs - always with a different reason. Initially it seemed to coincide with steam downloading onto the boot drive. I stopped steam and ran the windows system file checker which found no system errors.

Today I encountered another couple of blue screens...then nothing - the sdd disappeared and all I got was an error that no bootable media was installed. It did not show in the BIOS (only my other ssd did).

Occasionally (rarely) the boot drive would reappear - often with a warning about winload.efi (or something like that) not working properly and error code 0xc000000f but the recovery drive could not fix it and the moment I rebooted, the ssd would disappear again. 

At this point the ssd appears to have simply vanished from the system. I tried swapping it into the other m.2 port but to no avail. Sometimes I get a recovery message quoting error code 0xc0000185 - it has a blue background and gives the option to retry, press F8 for boot options (which does not work and just goes back to the recovery) or another button which takes me back to BIOS.

I have booted up a Linux flash drive and that could not find the drive either.

I am at a loss about what else I can do. Has the ssd failed? If so - how could it not even have lasted 18 months (technically there probably isn’t even a years use on it) - surely they are supposed to last a few years before this happens?

If it might be something else then what could it be? My worry is that surely windows could not remove the ssd from being recognised in the Bios?

Any help would be really appreciated as i am at my wits end with it.