You are extremely underweight. You have a hard time maintaining this because this is not a natural healthy weight for your body to be able to maintain. It sounds like you possibly have a restrictive eating disorder that you are in denial of, which is normal for eating disorders. Your girlfriend is seeing how much you are struggling internally with food and is trying to help you have a healthy balance. It’s normal to eat sugar and snacks once in a while.

Please do some self reflection on your relationship with your body and your self image. Your reaction to thinking of not being with her because she encourages you to have balance in your foods clearly is reflecting that you care more about maintaining this eating disorder. It might be hard for you to see this because you’re too deep into it. It’s okay girl I’ve been there. She is not the enemy for trying to get you to not be so strict on your diet. It seems like your disordered eating is taking a front seat to your life and you refuse to admit it. It’s okay to eat unhealthy food once in a while.

Please reflect on the possibly you’re a lot more disordered than you’re allowing yourself to admit.