Hi Steph,
With luck someone experienced at low-carbing with type 1 will be along shortly to recommend suitable insulin's, however can I just say that your DSN is quite wrong to say you don't need insulin to cover meals without carbs, protein in the absence of carbs converts to around 60% glucose in the body - but as you say over a longer period.
Today I had a 3 egg omelette with some low-carb veg for dinner and I needed 4 units of insulin to cover this meal, yesterday I had a chicken salad sandwich using Burgen bread followed by a fun-size banana to which I needed 5 units of insulin, so as you can see it's not all cut and dry excluding carbs!
Hopefully over time you'll begin to notice how much insulin is required to cover certain low-carb meals, it's really trial & error but recording & monitoring like you did on DAFNE should have your levels stable again.
Nigel