I would like to recommend a book for you to read. They fu@k you up, by Olivier James. I think you will find many of the answers you seek there. People trying to make you feel bad for not giving/doing what they want is not always healthy, works for small children, but as adults not good.
My sis is one of those people. I always stood my ground and didnt let her manipulate me. I feel sad for what her daughters have turned out to be. I don't visit them too often and even then they try to make me feel bad for not doing so.
It is an excellent book, read it years ago and it helped me a lot, probably need to re read it now. People do what they know and when they know better they do better. Honestly some of them are unaware of the way they behave, and how it affects others. But then as an adult you have to step back and say "hey how much of this is about me, and really how much is the other person's issues" and you go from there. You can't change them, but you can change the way you react. Unfortunately, people who are close to you know which buttons to push.
YES!!! that's how my family is they feel entitled to the fruit of my labor and they hate me because i refuse to give to those who are well and able.