Am I in the wrong with mum's new boyfreid?

basically, I'm a 15 year old girl , living with my mum, sister, and my mum's boyfriend for about a year. So basically I went out with my friend and i don't have a phone at the mo because it is being repaired. So my mum told me to take her phone so that she could get hold of me. I forgot. I know that it was a very irresponsible thing to do, but it was an accident, I didn't do it on purpose and I didn't mean it. Anyway I got home the next day, and me and my mum ended up having an argument about it. When we were argueing I was being quite rude, but I was very upset. Then all of a sudden mums boyfriend stepped in and started shouting at me! I was quite ahocked by this, and, to be honest, scared, because most of mums boyfrieds have ended up shouting, and then they start getting violent. So I fought my corner and told him that he shouldn't be getting involved because he wasn't related to me and so an argument between me and my mum was none of his business. He stormed off, mum sotrmed off, and I went to bed. About an hour later, mum comes into my room and tells me that because I fell out with her bloke, I have to move out and live with my real dad. I don't mind moving, but I want to finish my education in the school I am in, as I don't want to uproot myself. I asked why I have to move, and my mum said that it was because I am getting in the way of her relationship. I got quite upset at this because I am being kicked out of my house and I thought I was a little more important to my mum than that. Am I in the wrog here? Sorry for dragging on. x