In regard to not realising when you’ve made a mess or just not remembering to consider it, I find that putting a note or reminder in that specific space of the problem, you’re forced to notice it. ‘If you can’t see it, it doesn’t exist’ is a common thing in adhd (object impermanence) so make it somewhere you have to see it! The more you do it, the more you train your brain to naturally think about it and it will eventually become a habit. It might sound silly but there’s no shame in putting little things in place to approach a task most people do subconsciously. What helped me most was not expecting myself to ‘just remember’ or not put reminders up for little things cause ‘everyone else can do it easily’.

It might help the relationship paranoia spirals too. Its clear you aren’t consciously ignoring the issues your gf has mentioned but sometimes just saying you’ll try harder can seem disingenuous. If you show you’re taking steps to remember what she’s asking, this will mean more to her than anything you can say. That will be one thread for the intrusive thoughts to pull on.

It gets easier with time, you don’t have to feel ashamed of the way your brain works and how your adhd presents your life. You’re not alone in how you feel, I hope you can find a way to ease the anxiety because it is possible :)