Have you tried making a smoothie? Add in a ton of fruit, fruit juice, and frozen yogurt that you like and maybe some ice as well. The smoothie may go down more easily than solid food - plus, they're delicious.
And then maybe you can work yourself up from a smoothie to something more substantial along the way.
I am BIG on breakfast, and I almost always have fruit and Grape Nuts cereal with vitamin-fortified soy milk. Grape Nuts is probably the healthiest cereal you will ever find - so many nutrients and vitamins. My requirements and recommendations for a good hearty breakfast would be:
1) PROTEIN - to wake you up in the morning.
2) FIBER - to get things moving, if ya know what I mean.
3) IRON - for energy, and because many women are deficient.
Hopefully you can take baby steps and get your body used to eating something more hearty in time. Go slowly, don't make yourself sick. And in the mean time, if you know you're going to be hungry later because you can't eat a big breakfast, then bring lots of snacks! Hope it ends up working out for you.