hey, first off, you're squatting bodyweight, and that's good!
so it could be diet, and it could be technique. without videos it's pretty tough to hazard a guess. have you checked in on the starting strength forum? you'll likely get better advice than on this forum.
"dean ornish and dr. davis think the palmitic acid our bodies use for fuel while we sleep is poison if we eat it. zero-carbers like charles washington think the oldest fuel in our evolutionary history – glucose - used by organisms a billion years ago and without which the brains of modern mammals cannot survive for more than a few minutes – is an unnatural toxin if you eat it. both views ignore basic facts of medical physiology and defy evolutionary history." - kurt harris