What Causes Sudden Elevation In Blood Sugar Levels?

I am a type 1 diabetic with years of decreased kidney function. For over 10 years my GFR stayed around 29. Then when I went into heart failure a year and a half ago my GFR dropped to 12. The last time I saw my nephrologist about 6 months ago, somehow my GFR was at 53 (normal) and he said it had to be a miracle. Well, back in Nov. I had a stroke and heart attack the same day. I was in the hospital and subsequently underwent 2 heart caths within a 2 week period. Yesterday, I awoke with high blood sugar levels for no apparent reason. I worked all day to bring it down and finally did around dinner. I went all day without eating mucn of anything, except a tangerine which I immediately vomited up. Tried to eat some crackers after that and lost those too. I was having severe cramps all over (hands, feet, ankles, thighs, upper torso... all over. They were terrible and I was in tears as I couldn't work them out. I am so weak that I can barely stand without getting dizzy. I tried to get a shower earlier tonight but my upper body was so exhausted and my arms felt like I rowed a boat to China. I'm exhausted. I've eated today and consumed several bottles of water and coffee. I haven't thrown up today but I have only urinated a very small amount (a few thimble fulls) which is totall unlike me. What is causing this?

Carol