I think I might not be eating enough

Yesterday we got up early exercise and the first thing I did was eat a banana.  During the night I woke up with severe cramps in my legs so much so that all I could do was cry and pray they would let up.  They eventually did but I thought I might be low on potassium.  I think the banana help me get through the workout but I didn't think anymore about it till today.

I've been working out in the morning with Mr. Wonderful and in the evening with my exercise buddy.  We worked on toning using a balance ball.  Wow, was I sore today.  I worked muscles I never knew I had before and they were definitely complaining.  After working out this morning I just didn't feel quite right.  I fixed breakfast while Mr. Wonderful showered.  We had our standard breakfast of Southwest Egg beaters with cheese, and mushrooms with bacon, and fresh fruit.  I still wasn't feeling very energetic even after eating so fixed a Slimfast shake with Soy Milk .  That seemed to do the trick.

I've been eating about a thousand calories a day and I'm wondering if I'm not eating enough.  I know my body seems to be holding on to every single calorie thinking I'm starving and it could be a while before we see food again. I had a another shake this evening before working out.

It was a really hard day at work and I'm already falling asleep .  So wish me luck I'm on my weigh.