Wish I had some answers for you. Unfortunately I don't.  Just keep trying what you can.  Some people use pure honey packets just like you would a gel.  That is the basic premise behind honey stingers. Just keep experimenting until you find out what works for you.  You should aim for 200-300 cals /hour, 60g of carbohydrates, and sodium, potassium, and calcium.  If you can eventually get to the point where you can drink water, you might try endeurolytes from Hammer Nutrition.  They are pills instead of liquid or gel.  They might be more gentle on your stomach. 

Agreed that you don't have to eat for a half, unless you find that you are consistently running out of energy. I really don't drink much during races either, but I have found that coconut water and Cytomax are easier on my stomach than Gatorade...so it might be worth trying out some different drinks.

i would say try natural foods, that is what worked best for me. I used dates in my last full marathon as my sugar source and that worked very well...straight shots of GU and such create havock for me. Prior to running have you tried something like a smoothie or a Mix1 drink if you need some fuel in your system?  Again I also think coconut water being natural sits better for me

hope those are some ideas that might help