Not really a question for bodybuilders but I feel you guys might know, I didn't want to start another thread...
During the middle of a HIIT workout (ala CrossFit if that matters)... I face two barriers:
Out of breath - that's a given but I can pace myself accordingly. If I double over I can get my breath back in less than a minute.
But the other is that feeling of moving my body that is analogous to dragging a dead weight through mud that increases almost exponentially during the workout. No more will/energy to keep moving at all. Do you guys experience that a lot? How to combat this? Is it purely psychological? How can I tell? Do I just ignore this somehow?
Breakfast is the typical 2 eggs/bacon/mushrooms.
Lunch is usually a protein+starch+mixed veg of some sort (i.e. quarter chicken, rice, mixed veg)
Snack on bananas and biltong for the most part.
Supplement with a scoop of whey protein and creatine and one or two others once a day (Usually week days only when I train).
Supper is generally a pasta/meat dish with some added carbs. I change it up now and then.
Sleep 8 hours a day.
Though I train regularly (Almost every day) I don't think it is over-training as rest makes no difference, actually worsens it on return. I hate rest as it sets me back too far I feel - but I never train on Sundays and take the occasional week day off.
So I don't think it is either sleep nor nutrition :/ But #notanexpert. I don't exactly count calories but I don't eat unhealthy either as far as I can tell.
Maybe I'm just overthinking it and this is normal. I just want to find out if that feeling is pretty normal and is what you all fight against during such a workout?

Or if you all bounce around like duracell bunnies and being out of breathe or facing typical muscle burn are your only demons (aside from injury)?
I am frustrated with progress and I feel this is what is holding me back. Is that merely what simple fatigue is? Recommendations on pre-workout/foods etc... might be helpful. Having a banana or whatever one hour before doesn't seem to make a difference.