"So I;m thinking there is a low blood sugar problem but something else on top of that."
Have you tested your blood sugar to confirm this? If in fact you have low blood sugar (below 70) - that is a major concern all by itself. However, you would also have low blood sugar during the daytime and it is associated with diabetic conditions. Interesting site regarding low blood sugar here:
http://diabetes.niddk.nih.gov/dm/pubs/hypoglycemia/
Eating at night? What is your body mass index (BMI)? (You can calculate that here - http://www.nhlbi.nih.gov/guidelines/obesity/BMI/bmicalc.htm) If you are overweight - particularly if you are obese those conditions can cause significant sleep problems.
"Also doing yoga and meditation regularly.."
Have practiced a grounded, in body - chakra oriented meditation for more than 30 years. It helps with much more than sleep, but that's a whole different story. I meditate for a minimum of an hour each day. It's gotten me through thick and thin - particularly thick - PTSD from childhood abuse and combat and air disaster survival issues. Bottom line is without it I'd have been gone a long time ago. Thank you for mentioning it.