I love when there’s a new batch of TR users starting their training…cuz it means a new batch of VO2max threads!
As others have said — eat. That might be rough depending how early in the morning it is and/or how close to the workout you wake up.
You might also experiment with doing these workouts later in the day (but not at night!), if your life situation allows; just to see how your body responds.
VO2 workouts are no joke and the long ones, 3-5min esp @120%, require your best self to get ‘em done. A good warm-up, much longer than the 5min TR gives you, might be needed. These workouts create lots of stress for your body, priming and making sure all systems are online may be crucial.
You didn’t say if you’re failing/not completing the intervals/workout. There’s definitely going to be some struggling both at the end of an interval and at the end of the workout, that’s normal (and Hurd -1 is a toughie!).
Hang in there, the TR support group will get you through your VO2max misery!