Teenage son

by Mary
(Australia )

Hi. I'm a single mum to 2.
I'm at my wits end. My 16 year old boy waa fantastic until his now 22 year old sister moved back home. He does not listen to me but rather his sister, who is destructive, demanding and controlling.
She expects everything but gives nothing I return.
She dominates her brothers thinking and I feel she has turned him against me.
My ex doesn't make the situation any better. They think the world of him now whereas previously they couldn't stand him. It's all about money with my kids. Who can give is great in their eyes.
They don't realise I keep a roof over their heads good bills and cater for everything while their father does not support at all and never has.
They both take me for granted and put me down which has led to severe depression
What do I do?
I've told them to leave to their dads as I feel they are only with me because they can get away with things.
It was not always like this. They were great until their father came back into their lives with big money.
Please help.