Why is a relationship so difficult with ADD? [Serious]

A bit of background info. I got diagnosed with ADD some time ago and have been working on myself ever since. I have been in a relationship with an amazing girl for over a year now, but no matter how hard I try some things just seem really difficult to grasp for me. I love her to bits, don't get me wrong, but the way I love her is terribly difficult to not only explain to her, but also to grasp for myself. Right now I am transition from a young adult to being a person that can live on its own. I am having lots of trouble having enough time, and free space in my mind to do all of it. I often seem to let her down and have no real reason I can her for doing that. I want to be with her as much as possible, but at some moments I just cannot grasp that. This leads to infuriating situations on both sides and makes me even more afraid. This result in a downwards spiral mentally for myself and makes everything even more difficult. As of now I don't really know where to go to and would love to hear the response of other people in a "similar" situation. I just want to be able to express myself to her in the same way she does to me. Not having arguments, but just the love we share.

/r/AskReddit Thread