Ok. So seems things got a little cray cray today.
The long and the short of it is.. She slept better, thus we slept better. She is still waking for regular feeds every few hours and using the dummy after a very long feed allowed her to doze off properly instead of having tiny cat naps that weren't helping anyone. Ttl she probably sucked on it for 15min through the night. She has continued to feed and attach well today at regular intervals and we will see at her weigh ins if she is putting on weight. After all that is the best indication that she is getting enough and my supply isn't diminishing.
Whilst I was torn about using the dummy for all of the reasons that have been mentioned. It came down to the fact that having mental breakdowns in the middle of the night and feeling intense resentment for my child was not healthy for anyone either. So as with all decisions we make.. You weigh out the benefits and the risks and choose what feels like the best path for you at that time under those circumstances.
I have a ds6 also. So whilst I can and have been resting during the day. I still need to be functional enough to get him to school, help with homework and the like. It's not fair on ds to be lagging in school work cause mummy is sleep walking like a zombie.
We will see how we get on tonight and take it from there.