Conversion is an important element of Islam and is linked to rewards in heaven. Also as Fahad mentioned, as per Islamic jurisprudence, a man can marry and woman of the book ( Christianity, Jewish faith, Islam) but the book doesn’t allow such liberties for women.
Basically bro, you either leave her or convert. Islam also doesn’t allow reconverting back to the old faith, the punishment for a murtad can be death. Hence most Ex-Muslim atheists live in fear.
My suggestion is that you find a new life or a new faith, which will be painful.