Aggressive toddler. Losing my patience pls help

So this could be long I’m not sure. I’m just so tired and starting to regret having my daughter. I know that’s horrible but she’s thrown me into a deep depression and I’m lost. My daughter is 25 months now. For the past few months, maybe even six months, she’s been mean. Really mean. She yells at me and she hits me, her brother and her father. If we say no or do something she doesn’t like (ex, breastfeeding our son, she doesn’t like that) she will hit, slam her head against us, throw toys, try to stab us with her plastic forks. She will get behind me and kick my back hard with both her legs. She smacks her brother and puts her hands around his throat. If she isn’t hitting us, she’s hurting herself. She’ll slam her head against stuff, smack herself in the head or legs. She’s even aggressive with the cats. She pushes them off the couch, throws them, grabs their neck. Now we try to correct this behaviour. We try timeouts, stern voices. We’ve tried staying calm and asking what’s wrong and why she is frustrated. But nothing. Works. We don’t hit her, no one in my house is aggressive like this so I don’t know where she learned this? All the shows we watch are paw patrol and peppa pig because she freaks if we watch anything else so it’s not learned from tv. She screams at us constantly and it’s to the point her brother can’t even nap because she’s throwing a tantrum 95% of the day. I’m trying so hard to be patient and calm but I feel like I’m about to give up completely. This is too much and I’m so defeated and depressed. Our bond is gone. We used to be best friends but I can’t do anything without her getting mad at me? It’s like I dread waking up because I know I’ll have to go through it all day again. I need a break. My in laws even take her for a sleepover every weekend to help out and she’s fine there so I don’t understand. I genuinely think she hates me. Over three months ago we had a new baby, moved to a new house and moved her to her own room in the span of 4 days. So she’s had a lot of change. But it’s been 3 months. She’s fine in her room and she loves our house and her brother. I just don’t understand. Whenever she’s like this( which is all day) I just bring her to a seperate room and sit her down and explain “I know you’re frustrated and sad and that’s okay but you can’t hit me, okay?” And then let her calm down in her own space and once she’s calm I go get her. But it’s not working!!!!!! I’m trying to be a good parent. I’m obviously failing. I have scratches, bruises, teeth marks all over. This isn’t normal. This can’t be just the terrible twos, right? This isn’t normal behaviour. I’m so done. I just want to disappear forever at this point. I want to try leaving the house more but I live in the coldest state and I’m all alone from 8pm til 4pm the next day. It’s impossible to get out because she makes it so hard with her and then having my son in the stroller. I’m struggling and I need help. I really need some help here