How much alcohol can I drink if I'm hypoglycemic?

None. You should drink none. See a primary care doc for the initial evaluation; then you may need the guidance and treatment of an endocrinologist, a gastroenterologist, a specialist in alcohol dependence, and /or a psychiatrist. If booze becomes a problem, suck on those who care about you, not on the bottle.
None would be best. Alcohol itself causes hypoglycemia in some people - it interferes with normal glucose production when our sugar becomes low. If you have reactive hypoglycemia, frequent small meals are important, and avoiding high calorie infusions such as simple sugars and alcohol is also important. Alcohol has twice the calories as sugar, and its metabolism can result in hypoglycemic rebound.