SSD Issues w/ Retina Macbook 15"

I think my laptop might be having SSD issues. 2 weeks ago, my laptop started freezing, beachballing, fans would go turbo, and then inevitably crash.

Occasionally, upon reboot, I'd get the question mark folder. Other times, not so much. I've tried all manners of safe-booting and even tried restoring my macbook from a time-machine backup. However, when I went into restoration mode my internal SSD wasn't recognized, rather a 550 GB (my internal SSD is 256 GB) was shown. I have no idea where this HDD came from as the only external drive I had plugged-in was my time-machine backup (320 GB).

Anyone else have this issues? I suspect it's my SSD or maybe my HDD connector cable.

The issue is very on/off, sometimes it boots normally, other times not so much. It has been crashing a lot over the last few days.