I’m not diabetic but I monitor blood glucose and ketones, just because I like to know what’s going on with my body.
I’ve had to have one of my cats put to sleep tonight so am feeling crap, and my glucose just measured 6.3 which is unheard of for me - normally the highest is 5.3
Could this be caused by the stress of this evening? I’ve not eaten for at least four hours.
I’m very sorry to heat about your kitty. As a cat-person myself who’s been there, it’s really tough and sad. 
Yes, cortisol can absolutely spike your blood sugar. Just focus on yourself and expect that your body will be doing some funky things outside of your control while you process this difficult.
Oh goodness me, I am so very sorry. I have lost a fair few cats and dogs and it is hellish. Yes, stress will totally spike your blood sugar. Take time to grieve and be kind to yourself. Hugs. xxx
So sorry to hear that you lost your kitty…that’s a hard thing to have to do, and nothing but time makes things better. 
Thanks everyone. I’m feeling seriously crap at the moment, no surprise as I’ve just lost a part of my family after thirteen years together. She was fine last week, had a slightly swollen face on Sat then on Sunday I knew the end was coming as she had got so sick so quickly…
Blood glucose was 4.6 this morning which is still high for me (normally around 3.9 - 4.2) and ketones 1.6 so i clearly need some time to work through this.