OP, my heart aches for you both.
I'm sure you'll get good support and advice from the links already mentioned above.
It sounds like the attack on your daughter has had a huge impact. Glad to hear you have professional help with this. I hope you're able to take time to look after your own needs, too, this must be very stressful for you.
As ever I think the most important things are connection, active listening, empathy and support, as well as setting firm boundaries. Teenagers aren't children, but all humans have the same basic needs - to feel safe, heard and understood. Sometimes children & YP kick against boundaries because they really want and need someone to firmly set them, if that makes sense.
My son was badly bitten aged 2 and went through a phase of biting me - I had to physically pull him off me and when I finally was totally firm and made it clear I wouldn't allow him to hurt me, he was able to process the feelings of hurt and confusion that he'd been carrying. Boundaries help a child/person feel safe. Empathic boundaries - not always an easy balance to get right, but I feel it is key.
Special time is what works best for us - I wonder about taking a holiday or setting a weekly two hours aside to spend purely with your daughter, and her alone, would help? Bearing in mind there may be emotional upheaval and upset as your DD feels safer and more able to open up. It's actually a good sign - that she feels safe, supported and listened to and able to talk.
Active listening is also an art - knowing when to be quiet, when to reflect and show you have heard.
www.ahaparenting.com/ages-stages/teenagers
A couple of books that may be useful -
Staying connected to your teenager, Michael Riera
Untangled - Lisa Damour
Wishing you both all the very best.