Unless you are supporting someone (could be a friend, family member or as a professional in your role at work) or you have experienced domestic abuse yourself, it's an incredibly difficult and complex topic to understand.
Which unfortunately means that lots of people victim blame when you reach out for help.
"just leave"
"it’s important to have your own money, independence, support network, etc"
"if it's that bad why don't you just leave?"
"I would never allow anyone to treat me like that!"
I genuinely don't think victim blamers mean any harm, they are just uneducated on DA so don't know what they are talking about or realise the damage they cause by their unhelpful "contribution" when you ask for advice.
Wouldn't the world be a nicer place if we replaced victim blaming with perpetrator blaming?
"why doesn't he stop?"
"why does he do that"
"what's stopping you from leaving?
"how can I help?"
Anyway answer to your question
Sadly with great difficulty :-) It's a real struggle
You will need to accept that it's going to cost you dearly but you simply have no choice - if you stay it will get worse - abusers don't change, the more controlling they are the more dangerous they are, and if you stay you will lose more of your life - which simply you can't put a price on.