I have read your updates.
You are in an emotionally violent relationship currently. This abusive coercive control and gaslighting is causing your emotional well-being to founder.
You are at risk of PND and that is not good for either of your babies.
Your DH is invalidating, minimising and silencing your very being - your experience, feelings, emotions and behaviour.
This is no way for you to live or for your babies to be exposed to.
You have already asked - he has refused and insulted you.
Don’t ask again. Get support emotional and practical to leave - and then to recover from this mess.
I don’t think taking on your DM, her hoarding and her own obvious MH issues is what you need right now. YOU need support and your babies need you emotionally healthy and balanced in a calm and peaceful home.
Speak to your GP. You don’t realise that you are in a very abusive and vulnerable position.
Your DH will not change. He is enmeshed and now neurologically programmed to put his FOO ahead of you and his children. He has shown you that’s what he does and believes in his words and actions.
You and your babies deserve way way more than this.