Harsh Night

I had a very harsh night last nigh, Around 11pm, I woke up with cramps in my legs, front and back.
From previous experience I know that either heat or cold will relive most of this, so I would normally climb in the bath tub and run real hot water over my legs with the sprayer, I couldn't even lift my legs the cramps were so bad so I settled for Ice I have several ice packs in the freezer, that only gave a tiny bit of relief but was able to sit on the edge of the tub and run hot water. I thought I was ok and tried to climb out of the tub and a cramp hit and I fell and hit my rib on the side of the tub..
If it hadn't been for Jim, I do not know what I would have done. Because as well as the cramps I had low blood sugar and wanted to throw up, and pass out, black waves were coming before my eyes. I yelled any thing with sugar and he brought me a spoon full of Nutella, and that passed. I was up for about 4 hours as I would think I could lay down and find out that was not going to happen.
I am not sure why I get these cramps but every time I go one a diet, it seems to happen for the first week, But it was never that bad before.
I am supposed to drink a lot of water and have been drinking about 3 liters a day and perhaps that is what washing all the potassium out of me.
Tomorrow I an going to the health food store and talk to the lady there, she is very knowledgeable, and hopefully can help me. I do not want to give up this diet as it is working and I am not hungry at all.
I will do an update when I find out what I can do about the cramps