Yes it is a normal post stroke symptom! As with all major trauma, healing burns energy. Because our strokes wounds are invisible we don’t tend to give them the same care as anyone with visible physical wounds. For good healing your body requires lots of sleep as it takes a lot of energy to heal and the brain needs it in order to process all it has relearnt as well as to rebuild and repair any damage from the stroke. It takes about 6mths for the initial recovery. This requires a lot of good nutritional foods and exercise as well so maybe a daily supplement to boost those nutrients is a way for forward, such as Ensure or Complan.
What I used to do, and still tend to, is make sure I’ve eaten something before I’d go for a walk for example. I’d also carry an energy bar around with me; in the early days post stroke I usually have eaten the bar half way round to give me enough energy to get home again. But I’m also type 2 diabetic so I keep close track of my blood sugar levels as I do a lot of physical resistance training at the gym, fitness classes as well as walking now. And I do have a blood sugar testing kit.
Here’s a link to another post I did about a year ago on the same subject:
In saying all that, and despite your BS levels being normal, I’d suggest you go have your bloods checked again. See your doctor as you may be lacking in a certain nutrient. Certain medications can quickly deplete certain nutrients in your body. I was about 6mths post stroke when I had my blood vitamin levels checked and was found to be severely low in folic acid. The doc put me on a dose for 6wks and I couldn’t believe the improvement it had on me. I hadn’t even mentioned my fatigue or the heaviness in my legs…it cured that within days for me, though I do suffer a level of fatigue but nothing like it was back then. I’m 63 and 5 years post stroke, though it was mild in comparison to many on here. So it could be very beneficial for you to see your doctor and have them do a little MOT on you 
Lorraine