I think your first few nights were good you weren't expecting the technique to not work for you because you hadn't yet experienced evidence that the technique wouldn't work. Expecting the technique to not work makes it less effective. When expecting the technique to not work, it's more likely that if a dream is entered without losing consciousness, the dream will be about the technique not working, which makes it more difficult to identify the dream.

Being a groggy sleeper is ideal for DEILD. Also, if you move around while groggy and are still groggy, then that moving around doesn't wake you up. There's a variety of ways to DEILD, so if one way doesn't work, you can try another way. Given your adhd, doing something while falling/staying asleep that doesn't involve a lot of constant attention would be easier to do. Maybe doing reality checks periodically while falling asleep would work. Use a reality check you are certain would work if you were dreaming and after waking up, do it every 30 secs or so while falling asleep or more often if you comfortable doing this. Once the reality check works your dreaming.

If DEILD doesn't work, you can try out DILD. Just try learning from previous dreams what the experience of dreaming is like to the point where in the future, you know you're dreaming when you experience it.