I almost teared reading your post. The issue is not with your MIL. It’s your husband.
The way he treated you when you were pregnant with his child (chase you out of house and scold you vulgarities) must be very heartbreaking for you.
A slap from a loved and trusted one is more heartwrenching and painful than being stabbed by a stranger. His mother may have given birth to him and raised him up, but you are bearing his child and taking on the responsibility of raising his child up for life. By permitting his mother to invade your privacy and psychologically abuse you, he is not a good husband. In fact, I find him to be of a worse character than your MIL. If your husband cannot be with you in your worst, he does not deserve you at his best.
You have a choice in your life. Yes, there are so many uncertainties if you pursue the divorce path, but the path further ahead may be filled with sunlight and butterflies. You may not want to hurt your children, but your children must be feeling upset by seeing you and your husband in quarrels and you in distress in the current marriage. If you pursue divorce, they may feel more relieved in not seeing all these arguments. You just need the courage to pursue divorce. I suggest you follow some people on social media, women who have been through divorce with children and emerge stronger eg Jacelyn Tay.
Hope these give you the courage to push through and cope with whatever that comes your way. And if you are thinking of finance as reason for not divorcing, 钱能解决的问题，不是问题。Most importantly is to live in healthy environment with healthy mindset.
Here are what netizens think:
Wah. Based on 1 post and you can ask people to divorce. You thought marriage is like building sand castle? After divorce if runs into problem you will help to settle? Children upbringing not perfect you can settle?
Not that divorce is not some no no solution, but at least not suggesting it by just reading 1 posting lah.