All of this.
Your feelings are entirely natural but, I agree with pp, you have terrified her.
Victims of domestic abuse need to be treated very gently and it can take a long time for them to recognise, accept and then come to a point to leave. Every step is scary, there's a lot of guilt and shame involved and intense feelings of love to deal with.
You need to back right off.
She needs to feel safe to open up to you, and that means no judgement, be careful of overt criticism of him. I wrote a post recently about supporting women leave from personal experience, if you search my name you'll find it.
Take a look at the info on refuge as well as women's aid.
Coercive and financial control are really hard for people to get their heads around.
I can only speak from my experiences, I'm not a professional, but in your shoes, I would apologise. Don't try to justify your reaction, just apologise and express how much you care. Blame the alcohol. You need to rebuild a relationship with you in which she feels she can trust you, where she won't feel pressured and where she won't be confronted with truths she's not ready to hear just yet.
Once you've repaired things, let her know youre there, try to keep communication open, be very gentle. She'll be alert now to you wanting her to leave so you'll need to tread careful. Quietly help arm her with facts as and when she's ready. This might be you gently letting her know that there's plenty of support available.
With so little control in her life, you need to help her regain control. That means letting her know you support whatever she does or doesn't decide to do, that you won't judge her whatever, that she can start exploring options but back out at anytime.
Many victims get panicked about choosing what they have for dinner on their own, so it's a process in helping them feel secure enough to break free.
There may well be other forms of abuse going on that she can't admit to. Don't pry, just listen if she opens up.
If you can't repair things at all but are able to communicate with her, then I suggest again you apologise unreservedly. Let her know that if she ever wants support or info you'll be there for her day or night, advise her to look up coercive and financial control and perhaps give her the number for womens aid. I'd be wary about using the term 'abuse' at this point.
Think about your role as a friend as gently clearing the way for her and providing her with a hand to support her as she picks her way through a river. You can't force these things, however much we may want to.