Uncontrollable Anxiety/Anger for Dad

For a long time now, myself and my siblings have a lot of anxiety and anger for my dad. He was always the parent that got pretty villainized in my family. We grew up watching a lot of fights and listening to my mom about how much anger she had towards him.

I don’t want to be angry and anxious with him, even on his worst days. Some days it feels uncontrollable when we’re taking care of him. His health is declining and we just want to be in a space of peace with him. We want to accept his choices and the now so badly but feel so blocked by our own minds on this.

Right now it feels like an impossible jump when what I feel in my body is so visceral and strong. Then I think there is some anxiety we want to keep like wanting him to be healthy and being worried and some anxiety that just blocks us from connecting.

Where do we start in sorting our thoughts and feelings here so gain a stronger and clearer perspective on our relationship with him?