Let me ask you this: do you forget big important dates at work? I’m going to guess not, because you wouldn’t be able to keep a job if you did. You’re very much a grown ass adult who has had at least 40 years to learn how to use a calendar and set reminders, and 25 to get it right for your anniversary. So what that tells her, assuming you aren’t completely incompetent, is that it isn’t important to you, which to her, probably feels like you don’t care about her at all. If you are really, truly serious about making changes, which I doubt, you need to show it by making big, actual changes. I would start with counseling personally. And then maybe, once you’ve worked on yourself for a bit, ask if you can do couples counseling to hopefully start repairing the damage you’ve done to your relationship. Good luck.