What are some real strategies for not being defensive?

I genuinely cannot deal with this anymore. Every time my girlfriend gets disappointed at me, mad at me or even criticises me in the smallest way, I get extremely defensive because in my mind im "right" and i see everything as an attack. I hate this about me and I hate making her feel unheard. She is an incredible woman and I would do anything to make her happy and not feel bad. For instance today I got super defensive because she pointed out I forgot something important and I immediately started being defensive and blaming the forgetfulness it on my ADHD. Which I know it is the problem but that doesnt invalidate her feelings or subjective experience. the problem is I COMPLETELY KNOW im in the wrong for being defensive but I dont know how to fix it.

My question is, how do you deal with this? Has any of you successfully become not defensive? I tried some strategies but I dont think I applied them correctly. I genuinely want to better myself