i agree with getting your iron levels checked again - and make sure they check ferritin which is your iron stores and maybe B12 levels also. I take a wonderful liquid iron supplement which is completely gentle on the stomach called Spa Tone - look for it in chemists or the chemist warehouse. My son also takes it as he has iron issues. Liquid iron is also more easily absorbed by the body than in tablet form.

Another bit of advice which may sound weird but a bit of exercise every day actually makes you feel more energetic - i know it can be hard to get movtivated some days, but set aside 30 mins and go for that walk or make yourself go to that yoga class !!
This also gives you time JUST for you, even if your children are wonderful - you still need time for yourself.

very best of luck - and please, try the spa tone stuff for a couple of weeks at least...and get those iron levels checked again.