I experience most of what you do and have always chalked it up to depression. I have depression and anxiety issues with a major genetic background in both. I've also had suicidal bouts and don't question the depression. Sleep issues and lack of motivation can easily be symptoms of it. I have problems with dissociation as well, and those made my t question whether I'd ever been assessed for ADD. However, it seems more likely to me that they're a result of childhood abuse (although I'd certainly be willing to take a test and find out).

Honestly, I'm not very familiar with ADD. And sometimes two different people can experience very similar symptoms and have different illnesses. So although I lean towards depression from your description of your experiences, I don't know enough about the alternative to say that it doesn't fit ADD.