I only tend to get tired in a workout if im not working hard enough.
If im going all out all the way through then im really energetic, but if i give myself a minute to two minutes sit down i dont want to get back up.

Make everything time coordinated. MAKE yourself get up after those 30 seconds are over, youll feel better for it.

It sounds more like a mental state that your going through than actual physical tiredness, fight it and you will pull through.