Dear @nur1507, Salam sister, how are you? I am sorry you are going through this ordeal, it's not easy.
But I want to be honest with you and let you know that this brother probably never had the intention to permanently marry you; it was just something he said to give you hope. He is taking advantage of your innocence and abusing the privilege of mutah, which I still believe is a divine mercy.
I am a convert too, but divorced with two children, so I know about these men who make claims to marry you permanently, but alhamduillah, I have my wits about me and my friends protect me too.
Are you a convert to Islam living in London? Please PM me, I am sure that we can support each other. I hope you're okay.