Hi OP,
I'm sorry that you're going through this but glad to see you came here for advice.
It seems to me, by your posts, that you know that the only answer is to leave. Your views on life, and faith, are not compatible. You are in the UK with certain freedoms. Do not censor yourself out of some false sense of loyalty or safety.
Anyone who says that they will leave you over your refusal to dress in a certain way, or because you don't want your daughter to dress in a certain way and because you are not a true believer and afraid to say so, is not someone you should be married to. You are there under false pretences. You say it's love but it is not love for this person. If it were, you'd be able to trust them and talk to them. You wouldn't have to hide how you feel or be threatened with being left.
Countless times, I have been told by Muslims that the hijab is "optional" and that women "want" to wear it and, countless times, I see that this is not the truth at all. This exact thing happened with three of my aunts who married into Islam. The difference is, their husbands were very honest about the fact that expectations weren't optional and that they disagreed with the religion. This is why they fled it during the 1979 Iranian regime change, in two instances, and similar reasons from a different country, in the other instance.
According to my aunts, uncles, countless other people I have spoken to and a book called, "Not without my Daughter," the religion is misrepresented so that you are lured in by false pretences and then trapped with children and instability and fear if you choose to participate or leave. Women will gang up on you, manipulate you etc to ensure you conform.
I think you know that you have to leave for your sanity, your safety and for children. Don't imprison yourself when you don't have to. You have freedom to choose. Don't waste it on trapping yourself. Reach out to the places some have suggested.
Wishing you all the best.