I just want to weep with you. My dd had anorexia for a year at 17, I did refeeding but due to rubbish support from a private charity and DP she didn't really kick it, just got to the bottom of the healthy BMI range. She's been a weird eater, anxious, depressive and generally struggles to stay happy ever since (2 years), and the latest thing is veganism which mainly consists of eating vegan Percy pigs and small quantities of vegan cheese.
I still panic every time she rings and doesn't leave a message, because of the suicide threats last time, and dread every encounter for fear of what state she'll be in. She's left home and is working and doing really well, but underneath is still fragile.
And yes she, or rather her disease, was violent, aggressive, rude, cruel to others, mainly me, and constantly angry, with the most foul and unpleasant language, and the better she was doing, the worse it was.
I got a lot of support then from this forum: www.aroundthedinnertable.org
And yes I am still absolutely ragingly angry at what this disease has done to her, me, and our family. To use the swear I first heard on this site, Anorexia can fuck off to the far side of fuck and fucking stay there!
I'm struck that often on here people being abused are encouraged to get angry about their abuser and to use the anger to find energy to fight for freedom. I wonder if this is a similar situation.
Courage, OP - you and she beat it once, you can do it again. Big Girl Pants all round.