When Caring Crosses the Line

I've always been the one people come to when they need help. I'm in my early 20s and live with an aunt who's recovering from a major surgery last year. She can't walk or take care of herself properly, so it fell on me to be there for her, round-the-clock really. I started out cooking meals, helping with personal hygiene stuff, that kind of thing. But as time went by, I found myself taking over more and more, from managing her medications, to handling her finances and even making decisions about her healthcare needs. It wasn't long before she was totally dependent on me for everything. I know it sounds crazy to say this out loud, but there's something incredibly empowering about being the one who has all that responsibility. I started dressing her up sometimes in cute outfits I picked out for her and making sure everything is perfect, down to how neatly her hair looks each morning. The other day she even said she felt like a burden and thanked me for taking such good care of her. It was then I realized how much control I actually have over her life now, it’s pretty amazing really, but also kind of scary. Is this okay? Am I crossing some line here with all the control and responsibility that's become mine to wield?