I empathise with you! My daughter is also very impulsive, even wreckless I would say. She started therapy two weeks ago and it is slow going. I'll share one thing that started working right away, though, regarding our daughter's practice of screaming and yelling in the house frequently. The therapist found she was screaming during therapy, so she implemented the following practice. As soon as a scream comes out, whatever she's doing stops immediately. We say, "oh no, you screamed/yelled in the house, which is not allowed. We have to go outside so you can let your scream/yelling out." Then we take her to the door and make her step outside and advise her to let your scream/yelling out. After she lets it out, we go right back and resume what we were doing before the scream.
The therapist taught us this on Monday, we implemented it at home and day care Tuesday, and were shocked that on Wednesday screaming and yelling had almost disappeared. Today at bedtime, she screamed, looked at me and said, Uh oh I let a scream come out in the house. I took her by the hand and brought her outside on the porch and advised her to let her scream out outside. At first she didn't want to do it, so I told her we would stay outside until she got it out. It took about 4-5 minutes for her to let it out. Then we went right back up to bedtime and she got right into bed, got tucked in and went to sleep right away. One warning, though. The therapist told us we have to do it 100% of the time she yells or screams. If we give her even one pass, it will all fall apart.