Left lower back pain from squats ?

[AlexLaid]

Hey everyone so I've been running ICF 5x5 for about 8 months. And as my lifts seem to be going up my squat is starting to suffer. I used to have knee pain but I fixed that from going too low. But now I seem to have real bad lower back pain. It's not my entire lower back but more on the left side of my lower back that hurts. My right side has no pain. And I'm creating this post to check that it could possible be my form ? I can't post a video due to the not enough post bull**** so I'll just post the link from my YouTube and maybe I could get some advice ? This pain is suffering me from adding past 170lb. Any help would be very appreciated ( it seems I can't post links either lol so ill just put the title of the video and search that on YouTube hopefully one of you can post the link for me lol it's titled "Left lower back pain Form check" and was posted today.

[FaIIen]

Well, core isn't tight and you're over arching - which could be a culprit. Try to keep your back neutral, there are plenty of bracing and squatting tutorials on the youtubes.