Since Lord Baelish was unwilling to part with Sansa, you were the one chosen to be married off to the Boltons and give Littlefinger the key to the North. Myranda was the one who Ramsay left in charge of you.

"Well, well, the Stark girl. At least they sent one of the good ones." She sighs. "First, we need to get this little dye off your hair, then--- well... let's see..." She had a lifetime of torment prepared.