Hi, Lam7615,
I feel you. My mom's whole family enabled her in one way or another until the day she died. Her brother, who is mostly healthy, was able to help her in a way that wasn't exactly enabling, but only because she didn't hold the emotional power over him that she always did over me. So he would sometimes ask me to help him help her in ways that were fine for him to help, but not okay for me to help (for example, giving her financial advice. There was no way for me to do that without putting myself in a dangerous place with her.) So I had to have boundaries with my uncle - I had to get to being able to tell him "I thank you for your care on this. I cannot do what you are asking me to, and I cannot explain fully why. But it is not a choice I am making out of anger. Thank you for respecting me in this matter."
Have you listened or read any of Brene Brown's work on boundaries? I'm just getting into her stuff, myself, and I found a couple of things in this video enormously helpful - especially the simple but profoundly meaningful assertion that "Boundaries are not division; they are respect."
https://www.youtube.com/watch?v=ecb6ExBaW80 Do you feel that you can boundary-set in regards to your aunt and uncle without having to explain yourself completely?