tweedlezee I don't have to imagine it - I have one DC with disabilities and another being assessed for SNs. Those same scenarios show up in my house on a regular basis. I get exactly where you're coming from, and it IS stressful. I'm not trying to make you feel bad. It's hard, I know. But I also know that you are feeling badly about it, and telling you it's okay without at least trying to provide other options wouldn't be very helpful.
My parents spanked us with a belt (and other things) and made us feel horrible sometimes. That's led to a very conflicted relationship with my parents, and I really struggled with this when my dad passed away a few years ago. I have a fairly decent relationship with my mum at the moment, however that is because we do not discuss this particular aspect of my childhood. At. All.
Because of my DCs' SNs, I have to constantly remind myself that their behaviour is often because of things that are out of their control. And I try to remember how I felt as a child when my parents were shouting at me and hit me. I don't ever want my child to feel that way. When I get too upset or frustrated or stressed over behaviour, I tend to sit back, take a deep breath, and try to calm ALL of us down. We do utilise time out for certain rules that are broken - "We do not hurt others." So any hitting, kicking, pinching, biting, and the like are "time out" offences. I offer them the option of sitting in a chair by the wall or going up to their room for the time out. I have always explained to them that "time out" is to allow them to calm down so we can talk about the behaviour that was naughty. So if they go up to their room, and can calm down in 2-3 minutes, then fine. They come down and we talk about the problem. If it takes 10 minutes, fine again.
DS1 often does the shouting, kicking, biting, and so on. I have found for him that asking him how he feels and inviting him to sit with me, cuddling, seems to help him calm down. He is just starting to learn to talk about how he feels. He's 7yo, but emotionally younger. If I were to get angry and shout back, he'd just keep shouting and getting worse. (I know this because this is what STBXH always does) He's still struggling with the idea that it's okay to be angry, it's a valid feeling, but that he cannot just do whatever he feels like doing when he's angry - he cannot take it out on everyone around him. It's a work in progress.
And it will take time for this behaviour to go away.