Unsolicited advice incoming but you rightfully put a lot of emphasis on the emotional dysregulation aspect of ADHD, which gets chronically overlooked.

Personally I have found that clonidine works really well for my experience of emotional dysregulation and rejection sensitivity. It’s a boring medication - typically it’s just used for lowering blood pressure and it’s quite safe and generally well tolerated. (Obviously stimulant medications increase your BP so taking something that reduces your BP as a side effect is actually beneficial in the long term.)

It might be something that is worth looking into for yourself given what you wrote here.

As a sidebar, I also experience PTSD and clonidine helps with managing my trauma response. One perk of the medication is that it’s fast acting and you don’t get major withdrawals from it so if I had a ton of trauma nightmares the night before or if I’m struggling with PTSD symptoms during the day for whatever reason, I can just increase my dose as needed on that particular day and it helps keep things manageable for me.