I find I do the same thing, complete with the repetition. It's horrible, I know, and it is embarrassing. I am in my early 30's. Ironically, I am also a caretaker to a sick parent.

In my case, I figured out that it was because I felt "out of control" of my own life and it was frustration bubbling up. Do you have someone who can relieve you of caring for your mother once in a while so you can focus on yourself?