Yes there is always that sense of obligation towards family. It is human nature to feel obligation to family and it is only people who have extremely low empathy who don’t feel that and you clearly are not that and that is also why I caution against full estrangement unless as a last resort for yourself because it has a very heavy price for you.
It does not stop these feelings and it can create more bad feelings than necessary with no where for them to go.
If you can start to put a bit more emotional distance in with them, just be more practical in your focus and dealings with them, it can make things easier. Basically reminding yourself that you are not responsible for them.
I mentioned at the start we had very difficult family, my FIL was incredibly abusive towards MIL and he was also deeply controlling. MIL refused to leave until eventually the police and social services were involved in more or less kidnapping her out of her home to live with an adult child as she was incredibly vulnerable at that stage but it never changed her relationship with FIL which was chaotic right until the end.
DH had to do what he could in terms of caring for her but equally care for his own well being in the situation, because the situation was a complete head melt and MIL would have taken her children down with her, she was at a stage in life where her own needs were all she had the capacity for.
There was tonnes of external pressure due to her extreme vulnerability (illness) and tonnes of guilt which never let up until his mother died but he refused to let that influence how he was handling the situation. That is my advice for you too. Don’t go in there with the expectations from functioning families go in there with the reality of your family and take care of yourself too because no one else will.
I cannot stand when people try to manipulate and shame and blame and criticise people who are caught in these situations from the outside because I saw first hand the sheer amount of emotional strength DH and us his family needed to deal with situations like yours @Wandawandswanda you deserve better than this and I truly hope for the best outcome for you.