Dealing with the aftermath of my mother's assault on my niece

Trigger Warning!!! Child Abuse, Assault, General unpleasantness. So I've been put in a situation I never thought I'd be in. Back in May I discovered my mom attacked my neice. For background shes been living with us since she was around 15 months old and is currently 10 along with her brother who is 13. I don't know how to describe it etc to be honest. We have cameras in our home strictly for safety etc. one of these cameras were in the living room during rhe attack and caught part of the confrontation. I don't know how much detail to share etc but the summary is this: I had gone for a nap but was woken up as I could hear my neice wailing and saying ow. I got up to investigate and found her in the living room with my mother. I got to mom popped her in the head or mouth but my neice seemed genuinely hurt. I convinced my mom to go shower and leave my neice with me. Once alone she told me she had been struck multiple times in the head. I got her an icepack and looked her over for any injuries as things were very odd. I didn't find any but later I remembered the cameras and went to see what happened. It was pretty bad, it caught my mom hitting my neice in the head and back of neck multiple times raining blows before she slapped her in the mouth and returned to her seat. I was blown away to be honest as my mom has never done this to either child ever. I at first was numb and made myself ill with worry before determining as my neice and I shared a therepist I would talk to my therepist about it. Well I did and she watched the video and things blew up from there. She called the cops (it's her job) and the kids were taken by cps of course temporarily. Almost a month after my mom was arrested for charges of assault against a minor out of the blue a few days before the kids were due to come home again. She was bailed out by a sibling and since the kids were taken and she was arrested my anxiety is out of control. I feel I'm tettering on the edge of a cliff 24/7 now. My mom found out through cps I reported it so there's also that in addition. Also I am unable to work and have been waiting for my disability interview due to severe social anxiety and cptsd etc. Thus I have no income to leave or nothing if and when she is jailed for good if it goes that direction. I am terrified that I will have to testify against my mother as well since I reported it and such which is like nightmare fuel times a million as I can't do people especially men. I don't know why but I needed to rant and I don't know how any of this judge stuff works or how to deal with my anxiety. My med provider has upped my doses but it's literally doing nothing. I feel like I'm going to pass out or hyperventilate every day that passes now. Now to be clear I don't regret protecting my neice, I know it was the right thing. I'm just so anxious and overwhelmed as my future housing and life is in danger. I'm worried I'll become homeless at this point or literally die at the hands of the stress as dramatic as that sounds. I wish I could ask advice etc but my therepist can't discuss anything of the case etc of course as she is my neices therepist and she could lose her license etc which I don't want her to jeopardize as she's a lovely lady. I only have my boyfriend to talk to but he's only one person and when he's not available I have no one else. I do talk to my siblings about what happened etc but it just seems like no matter what I'm alone or they don't fully understand how I feel or am going through. They just tell me to stop worrying and to wait and calm down. They aren't aware thats impossible for me and I don't have that luxury. Life is just even more complex now...idk what to do or think anymore.