My dad and his girlfriend have been together for about a year now. She moved in with us pretty quickly before we got to know her, but I thought she was nice. About 2 months after she moved in we would be open about our things, we'd share everything and sometimes wouldn't even ask (herself included would take my makeup hair straighteners etc). She soon started to change and get overly jealous of mine and my fathers relationship, interrupting me when I spoke to him, coming in between us when we were walking next to each other. I thought nothing of it until I heard her arguing with my dad about how I do no cleaning in the house, I get up at 7am for school and don't get home till 8.30 some nights, and I work on weekends till 10pm. My dad of course defended me but she continued to complain and call me lazy and "no good". This really hurt me and I grew apart from her setting boundaries with my things and so did she. A few days later she started to complain to my dad that things had been "going missing" and she even claimed to find things of hers in my room (I assure you she did not I have never stolen in my life and would never steal nail varnish and a run out mascara). My dad asked me of course and when I denied it he believed me instantly.

Just after this her and my dad went on a night out and they had an argument while out (because my dad said he'd never put her before his kids) she came home and woke me up (around 2am) saying "I think we need to talk you theif" and started accusing me of stealing money out of her purse. She said "money would be in my purse and when you came home I checked and it was gone" now bear in mind I work, alongside getting money from my mum every month, so why would I need to steal money? She was drunk and started pushing me calling me a liar and saying I have stolen from her since she moved in.

My dad came home and told her she should stay in her mums, I went back asleep but when I woke up she was in the bed with him. I don't know what to do because I am so hurt that he took her side and hasn't even mentioned it since, he's pretending nothing happened. She's put a lock on her bedroom door and keeps making remarks like "put that away Caitlin might come round and it'll disappear" I feel worthless in my own home and need advice. What should I do?