I want to marry my cousin

Assalamu alaykum

I will lay it out as it is…

The issue is that I want to marry my cousin. I informed my mother, who then told my aunt.

My aunt revealed that she had been married once before. One day, her brother (who is also my uncle and the father of my cousin) was sitting at a table with her husband’s brothers. On the table, there was a glass of water, and my uncle claimed that he knew how to use black magic to freeze the water in the cup.

The husband’s brothers told their sibling about this claim, and he went to confront my aunt. He accused her of knowing black magic and claimed that her family practiced it (which was not true). This led to a terrible divorce. She also revealed that my uncle had his children before he got married (zina). Additionally, she claimed that my uncle and his wife had insulted and sworn at his mother in her face. She also claimed he has sakht from his dad.

My mum doesn’t want me to marry her because she believes that the actions of my uncle and the results of his actions will come and manifest in her, like “kama tudin tadan.” She believes Islam says he will be punished through his kids and/or grandkids. She doesn’t want me to be a part of that. She thinks she will come to have sakht like her dad.

For as long as I can remember, my uncle has been religious. However, he has a reputation for telling lies and being untrustworthy within the family. His relationship with the family is strained, and many members wish he wasn’t part of the family, wishing he wasn’t their brother or relative.

My mum wants me to break up with her. I have been performing istikhara for a few months during Ramadan to seek guidance from Allah on this matter. During Ramadan, I did not talk to her as frequently as before, but I am unsure whether it was a sign from Allah or just a coincidence due to our busy schedules. At the moment, I am completely lost and unsure of what to do.