Hey you first of all: This is not your fault! everything looks so clear in hindsight - but you've done what you've done for good reasons.
Next: you need to leave. Now. Take your kids and move where ever you have to. I'm not sure, do you still have family? Call your mum - I'm sure she'll take the three of you in, untill there's a better solution. And if that's not possible, there must be other ways - places they take in women whose men is abusive.
And lastly: don't listen to him. You're smart to start studying. You should keep going, whatever he says. He should not be able to ruin your dreams. Don't listen to him, and get out of there.