I think to honestly answer your question requires more context than we can get from one sentence over the internet.

Cutting out abusive people is wise and prudent. Cutting out flawed people who care about you can be tragic for everyone involved.

Telling the difference can be hard.

Self help books that have helped me include Meditations by Marcus Aurelius, Peace is Every Step, After the ecstasy the laundry, Eat that Frog, the book of joy, Man's Search for Meaning.

You may benefit from counseling, or from honest feedback from a good friend. If you want advice about a specific person, Momforaminute or r/askwomenover30 are nurturing communities that might help.

TLDR some self help books are bad books with counterproductive advice. Some are useful.