I can SO relate! My wife and I have been married over 20 years, and I just found out about my ADHD a few months back, but we have been struggling in our relationship for a long time. We have fallen into the classic parent/child relationship because she feels I forget things all the time, and irresponsible and has taken on the “Mom” roll which is SO TOXIC. She resents it, and I feel like dirt to much of the time. We are now trying to figure out our relationship and where to go from here. Everyday I wake up hopeful and then crash and burn on something stupid.
The best I have discovered is try to talk it out and discover together the challenges of being in a relationship with someone with ADHD. My counselor suggest small steps, that way there is some success every day. Ultimately you are who you are. There are tools to use to help manage better with other people, but your partner needs to decide if they are willing to work with you as well. If not, then that person may not be the right person for you. It is tough, but if they are willing to learn with you, there is growth and understanding.
Best of luck!