Advice of not being forgiven by a parent

I have always been very outspoken, I’m the black sheep of my family. But I also say the truth, sometimes in a mean way without truly noticing it. I guess I used to not know when to stay quiet and what was ok to share. 7 yrs ago my siblings and I where talking about our mothers cooking, how she puts to much oil and it made us sick. Well I mentioned it to her and instead of taking it as a “oh ok, maybe we can try a different cooking oil, or less oil”. She took it so personal as if I was attacking her and boom she gets diabetes and since then blamed me for her diabetes. I didn’t mean for her to take it to heart and idk why she’s so emotional and how she’s not been able to forgive me after many years! She’s catholic and prays daily but she’s also very ill, the diabetes because of her lifestyle is getting worse & I’m having to live the burden now that it’s my fault! When I mention “hey mom, maybe stop eating bread and sugary stuff in the am and night will help you feel better!” Her response is, it’s not the food, it’s the way you treat me. Idk how else to help her, I’m trying to cook for her healthier foods (which she never likes or eats) and again it’s because it’s my fault and I try not argue with her, but she’s always trying to argue with me for random stuff. It’s like if her anger towards me is never going to stop. Please if you have a moment pray for us