64-Bit Kernel Suddenly Missing/Not-Bootable after Yosemite 10.10.5 Update

Seen this in an old thread which had very few answers/responses so figured I'd try a new one...

I recently updated to the latest Yosemite 10.10.5 on a late-2011 13" MacBook Pro and ever since I'm having an issue where 64-bit kernel has gone MIA on my MacBook and as a result it is causing all sorts of kernel panics, software crashes and also random crashes of all the main internet browser. I have always booted into 64-bit but now it doesn't seem like it is an option anymore. The worst part is that beside battery life being poor these are issue that didn't exist prior to this latest update. My laptop is practically unusable at this point.

Up to this point I've tested the RAM in diagnostics mode and it checked out okay. Did NVRAM and SMC resets. Repaired all permissions and disks. Even went as far as to wipe HD and re-install OS X Yosemite from scratch. Still having same issues though. It's as if something has permanently happened to the 64-bit kernel and now everything is crashing because it's gone MIA... My next step would be to roll back to an older OS and see if same issues persist...but I fear that'd be pointless as whatever pertaining to the 64-bit kernel that might be missing is now a permanent problem...

Previously I had the 64-bit verification in System Software Overview display... These aren't my photos but they demonstrate the problem.

But now that particular field is gone in the same profiler whereas I remember seeing even in the previous version of Yosemite...

Also I tried to use a 3rd-party app...one which I've never had a problem with before...to verify what was happening. Previously when booted into 64-bit and loaded up the app it would display as such...

But now only the first four fields show 64-bit while the last one is stuck in 32-bit not matter what I try to do...

Can't use the app to force it into 64-bit, can't hold '6' + '4' on reboot and can't even modify the boot file to permanently force it to boot into 64-bit. Like I said before it is as if the 64-bit kernel or whatever system files that control it have gone missing.

Called Apple and when to Apple store but both option just resulted in them saying it is possible that the logic board coincidentally failed at the same time I updated the software so their default response was to book it in for a logic board replacement. Because the laptop is long out of warranty or Apple Care I was actually waiting for a new retina MacBook Air to come out. But if I were to replace now I'm stuck with the underpowered new Macbook and a non-retina MacBook Air. I'm also not interested in the 13" MacBook Pro as portability more of an need at the moment. Spending $600-$700 on logic board replacement on a four-year old laptop is also out of the question. That leaves me in the uncomfortable position of trying to fix while also babying this laptop along with it's constant kernel panics till an announcement is made.

Obviously in this situation I can't help but think it isn't just "coincidental" as the Apple protocol would say. Also can't help but think if this is the old conspiracy theory of "Apple Planned Obsolescence" in action but considering the timing of how things went suddenly belly up it wouldn't be out of the question.

Anyhow any input or feedback from people with similar issues would be much appreciated. Thanks in advance.