Tried Roleplaying My Dark Fantasy

I've been feeling this urge for a while now, something dark and taboo. Wanted to try it out, but my partner doesn't share that side of me. We agreed to take things slow, explore other stuff together instead. But last weekend, I couldn't resist anymore. Found an old costume from high school drama club, put it on. Went through the motions, pretended someone else was there with me in this dark fantasy role. Wasn't about anyone real, but felt so real. Felt like every secret desire building up inside came rushing out as I touched myself. My body didn't care that no one was watching, just wanted to experience it all. Knew it wasn't okay to act on it with another person, but doing this alone helped me feel a little less trapped by my own mind. Shame hits hard when I think about it though, wishing I could confide in someone without judgment.