Please help me!!! as soon as possible?

Me and my dad used to be soo close but ever since he met his girlfriend he acts like he cant stand me I really miss having my dad around on my birthday he yelled at me he only does it around her so I think he is trying to impress her but anyway she takes my clothes and wears them and streches them out and when I tell my dad he told me not to accuse people and she also stole my brand new very exspensive perfume you can hear them doing it eww and shes only around when my dad gets paid he spends his whole pay check on her then she leaves and he gets mad is I say I want something what should I do?