Anger management

TLDR: I (F21) feel dominated by anger and I get so mad despite using the skills that I know about. I want my boyfriend (M24) to feel safe and understood, that's why I'm trying to manage my anger differently. What skills work for you and how do you manage anger overall?

Me and my boyfriend are a couple since May, we are still working on the base of the relationship.
I (F21) am a deeply opinionated person and I stand by my beliefs and morals.
My boyfriend (M24) is having a hard time to keep calm as well, especially when I am so easily triggered.
I always try to advocate for my morals, but lately (1 year+) it has become incredibly hard to just calmly talk. I hear something infuriating for me and I get so angry, I kind of drift from the topic itself.
I know I get angry because I feel misunderstood or not understood at all, because I think my boyfriend is inflexible and intolerant, but it is not always the case. It takes time for two to understand themselves, and I can't get there without getting angry.
I have always been a person that didn't get along with different opinions of the stuff they really care about. It's really hard. And I also have ADHD which I am trying to manage with meds but they don't really work. This makes my emotions feel so intense that I feel my chest burning out of happiness, anxiety, uncertainty and also... anger (which is the worst).
I am in therapy and I tried to find skills that work for me. I tried deep breathing, taking a break before speaking , progressive muscle relaxation, meditating more, but nothing seems to help until I finish an argument. I end up being really mad and acidic, basically impossible to talk to. I realize that is happening and I hate it! I hate it right there, on the spot.
I usually say I have to take a break but it's hard to come back to it, as I tend to run away from lashing out.

I'm curious about what skills work for you and how do you manage your anger when it's really, reallyyyy intense?