It's probably the protein. Not eating fat should also feel horrible too, messing hormones etc.
Source: Pretty well known in keto epilepsy/cancer/psychiatry. I do epilepsy keto diet. Having high protein will increase glucose & lower ketones (tested blood many times with just 2 ingridients beef & beef fat). I aim for 80%-90% of calories from fat. Or 2 to 1 weight ratio of fat and protein/carbs.
For T2D you probably need just 60% fat calories though.
