I'm in love with my twin sister, but i don't feel guilty...?

we're both girls. i told her about our step brother, and she told our parents. they chewed him out and sent him to live with a relative of ours for a few days. during which, i started fawning over my sister. i don't know why, i just couldn't resist. i cuddled up to her on our bed, and started licking her neck while she was asleep. i could tell she was enjoying it. then i started kissing her, she woke up and started kissing me back. she slipped her tongue into my mouth and frenched me. it was so incredible, i lost myself in the pleasure. when she stopped, she asked me why i kissed her. i told her i think that i'm in love with her, and i asked her why she kissed me back. she hesitated to answer, but eventually said she was trying to beat my kiss. i was confused for a moment, and that's when she stuck her tongue in my ear. i slowly fell to the bed and closed my eyes. we were so in the mood, we continued to make out, and began scissoring. it was the most amazing night of my life. since then, my sister and i have been frequently intimate. i enjoy my skin-ship with her, and as long as we're touching, i just feel so safe, like the rest of the world is a far away and nonthreatening place. i want her to hold me in her arms forever, but i know i shouldn't. what do i do?