Gosh I feel like I could have written this, this was me 2 years ago. We were desperate. My husband actually said I am going to write in a journal that you were the WORST 3/4 year old ever. It's exhausting!! I swear we didn't sleep for 2 years either. We actually worked with a parenting coach who's an expert on here (@SustainableMama ) mostly because I felt like we kept trying different things and approaching the situation differently, and then I would approach it one way, and my husband the next way. The parenting coach was able to give us a strategy that we BOTH committed to, and we were able to stay consistent with our punishments, strategy etc. Our girl is now 5, and although it has gotten better she's still my more emotional one.
No sure if you are religious, but I pray for specifics and her on a daily basis as well as for patience for me. It's interesting to watch, over the past 2 years although she is my most difficult she is the one closest to god and has the strongest faith out of all my kids. All this to say it's hard mama and you are doing a great job!!