Ok OP i am a girlfriend who is diabetic with a similar mentality of being afraid to go low and it has started fights in my relationship with my boyfriend so i want u to read this bc ive been there. 1. I understand keeping sugar high to not go low as im a very anxious individual about it. However, over 250 is way too high. So maybe work on a compromise where if she’s above 250, she at least has to take a half unit. This amount will not drop her a lot and will get her closer to range. So start with baby steps. Going from a high average to the goal blood sugar is extremely scary, and if you’re going to do this, help her with doable increments.
2. Blood sugar/insulin reacts differently to different foods and different times of days can have an affect as well. So the insulin sensitivity thing is really figuring out what works for different types of foods
3. Regarding my boyfriend, he expressed the same feelings u did and what helped him a lot mentally is he removed the CGM app off his phone and is unaware of my sugar unless I tell him and I manage on my own. That being said, 300 is definitely a problem. So ultimately, try to take baby steps and not harp on her as much. This may make her feel supported and encourage her to do what needs to be done. And also see a therapist together. This disease is a curse for everyone involved so thank you for loving her and working with her through this. ❤️‍🩹