Salaam, 

I live in the uk with my parents and siblings. 
I want to ask I am now 25 years old and a Muslim. 
I am in love with this guy and  it’s been 3 years.
I told him recently and he’s from a different Religion.
We both are aware that this will not lead anywhere. 
His family would not agree and my family would 
never accept it. 
We thought about him converting so I asked my mum if I can get married to someone 
who converts to Islam and she said no. I don’t want 
to go against my parents decision plus the Nikah won’t be valid until I have my parents consent. 
My question is that I don’t want to accept anyone else. In Islam can a girl say to her parents that she doesn’t want to get married at all? 
I am from a respected family and I haven’t done anything wrong since he found about my feelings towards him we don’t talk anymore. He knows my family will never accept it and I can’t accept anyone else as my husband.