You could try upping your carbs a bit, Sirzy, and see what happens - you can always drop them down again if you don't like the results. Try going up to 50g, then 70g first, and see what happens. Grazer's suggestions are good. I always find I crave a few more carbs at this time of year.
The other thing about this time of year is lack of sunshine, which means lack of Vitamin D. This can make you tired. At the latitudes we live in, the winter sun is not strong enough for us to get enough Vit D, let alone the fact that we don't expose enough skin in this weather! We store some of what we make in the summer, but not enough to get us through. Also, as we get older we make less Vit D. It's almost impossible to get enough from diet alone, though your eggs and fish should be helping, also your vitamin tablet. I take quite a lot of Vit D3 (which is the sort we need to supplement) summer and winter alike. Less in summer. Have a search around on Google - there's quite a lot on there about it. I take far more than the RDA - you must make up your own mind on it.
I also have a SAD lamp (daylight replacement) which sits beside my computer. I have it on while I'm working, and it does help.
Another thing that can make you tired is an underactive thyroid, which is often associated with diabetes. It can also give you things like thinning hair and a dry skin. Google 'British Thyroid Association', or similar, and check out the symptoms. It's possible to have an underactive thyroid even if your tests are within the accepted range.
Finally - when you've armed yourself with all this knowledge
go along to the doctor and have a thorough discussion with your GP. In my experience, you shouldn't run out of energy while low-carbing, even if you're exercising. I used to walk 25 miles a week with the Wolfhounds while doing Atkins the first time, and always had plenty of energy. Mind you, we are all different - so check Vitamin D3 and hypothyroid on the net, and then go and talk to your GP.
Vitamin D tests are expensive, so they might not give you one just on asking. That's one of the reasons it's always useful to do your reading round first.
Good luck!
Viv 8)
PS I thought sheep nuts were very high carb, Grazer! all that cereal :lol: :wink: