Q: IOUSBHostFamily Kernel Panic after El Capitan update on SSD

Hi, wonder if someone can help me diagnose this. I've been trying to upgrade from Yosemite to El Capitan for about a year now, to no avail.

I have been a happy owner of mid-2012 mbp for a while, but when El Capitan came out, I came across this weird problem, where on first boot after installation I get Kernel Panic and can't even get to safe boot. The only culprit I can see is the SSD (Kingston shfs37a 120GB) drive I have installed in place of the older HDD that the laptop came with. I replaced the SSD with another brand/capacity (Crucial MX200), same effect, as per below:

Kernel Extensions in backtrace:

com.apple.iokit.IOUSBHostFamily(1.0.1)

init: error getting PHY_MODE

I am quite proficient in Windows and Linux, but not so much on Macs, so can you guys point me in the right direction? I ignored El Capitan altogether but now with Sierra coming out I decided to give this another try.

Any good soul willing to lend me a hand?

Thanks in advance,

Mac