I'm sure I am not alone. My dm has struggled her whole life with mental health issues (grief, depression etc) and often lay in bed and let us send for herself. She can be bad tempered and attention seeking and terribly unkind.
I suffer with low self esteem and find it difficult to be comfortable in my own skin but am now older and wiser with a lovely family. I cope by reduced contact (visit once a week though she bullied me into two to three visits a week for many years). I went nc twice and my df wasn't much use and No one contacted me in that time.
Now my sibling has moved away due to personal problems and dm is all over me again. I keep my distance but things are better - she knows she can't mock me or criticise me or tell me I'm boring and all her usual stuff or I won't see her for months.
She now contacts me to say she is getting help for depression but I feel it's too late to heal all the wounds. I know a spiteful hurtful put down is never far away and I will never get close again.
Phew ... good to get all that out.