It's fantastic that you want to help your grandmother, even though she's treated you poorly. I think you're definitely wanting to do the right thing. That said, you shouldn't have to put up with mental abuse from anyone. Older people, particularly at the end of their lives, can get fairly abusive. (My grandmother did.) Is there anyone in your family you can talk to about this, to find out if she's spreading the abuse to others? And if so, is there anyone who can talk to your grandmother's doctor about the abuse, which could be a sign of other problems (such as depression, bad reactions to medications, or even demensia). It's also good to talk to others for help. You don't mention how much care your grandmother needs (if any), but if it's just you and her, and she's got heart problems, this is going to be important in the long run. If there aren't family members, and you don't feel comfortable talking to her doctor, try to talk to the teachers or counselors at your school, or any adult who you trust. There are organizations out there that can help families in your situation. I'd even contact the local branch of LAMDA - they may have suggestions on how to get along better with your grandmother, too. Good luck - it's hard, but you're trying to do the right thing, and that makes you a fantastic person.