As I appear to have primarily insulin resistance issues, I don't usually get the specific problem Gary was describing. My problem is 99.9999% insulin too slow... although tail end carbs still can be a factor. As I have the pump, I can also use slow released boluses which can really help solve the effect of held up carbs.
Does info help you? Not really... sorry... but I'm getting to maybe some more useful comments
I too get very "nappy" with certain types and certain amounts of carbs, which along with spiking continues to drive my ongoing interest in experimenting with lowish carb eating.
With your nappishness, it's important to recognise that there are (at least) three things that might be going on.
First, you might be getting nappy because your BG is dropping, due to the effect outlined by Gary.
Second, you might be getting nappy because your BG is spiking quickly with the carbs, despite the fat/protein (even an "acceptable" spike, if fast, can produce side effects).
Third, you might be getting nappy because you could have an allergy to the carb, that you are just getting "tuned into" especially now you take so much more notice of your food and body with your newish friend diabetes.
Fourth, it could be a combo of these effects. What would be useful would be to test test test at say 10 or 20 minute intervals a couple of times to see what trends are going on at those times you start feeling nappy. I know this is hard considering your terrible ration of strips... but such things help clear up all these perplexing possibilities...
The other thing to remember is that, while the info posted by Gary is very good info, it also stands to reason that if you minimise or remove the carbs for a certain meal/snack, you don't need the insulin in the first place... you do'nt have as iuch insulin in your system, and then these dynamics may well be much minimised. I'm not advocating a low-carb diet per se - just more to consider to consider for problem situations.
I also thing that low GI options for carbs are always worth heading towards and experimenting with. Out of interest what are you using for your morning tea? With lower GI, whenever they kick in, they should have less of a spike. Note that low GI for others may not be low GI for you, you need to test, but the lists you can find around can be a great start for experimenting.