Wind can be really tough. I ride my bike up lots of very long hills but I think a headwind in the flats can be way tougher to deal with at times. Its mentally grueling which for some reason translates into physically exhausting. Personally, I have a theory that this is to do with pacing, you can pace a ride up a hill better because you can see it. Wind is different, especially solo if you have nobody to draft off of. The chances of riding the wrong pace for the conditions is greatly increased IMO. So you could feel like you're bonking but you're really just fatigued.

The only reason I said not to fear carbs on the bike is because they are this super-readily-available fuel and other people were telling you to avoid sugar because of the possibility of the insulin spike and then blood glucose crash. I'm not saying that doesn't happen, just that it is not a problem for everybody. My big point is that the more intensely you are working the less you can digest things. So I fuel pretty much with sugar on any ride I expect to be taxing, that's what Cliff Bloks are- sugar (and caffeine). I do this on purpose so that I don't have to deal with digesting anything. I might eat a Cliff Bar on a long more social ride.

Normally we think of eating things like sugar as being "bad" and things with fiber or protein or fruit/veg as being "good". These same nutritional rules don't necessarily apply on the bike, because you're eating for a different reason. Think food as fuel rather than fuel as a source of nutrients. There is actually more to this than what I'm saying, some people try to start recovery on the bike by consuming protein on rides. Personally I can't deal with tons of protein while riding, so I avoid. But it works really well for many people. So again, just realize you have to figure things out for yourself, those are just some thoughts to help you make nutrition decisions as you ride.