I feel the pain. During the build phase, I really REALLY hate my early am rides. I can do better in the afternoon but that works less with my life.
If you are only dropping the intensity by a couple of points, you are still within the range of error (5%). Do it, nail the ride. Claw your way back up.
I’ve done GB mid volume three times so far and each time the last few weeks are very difficult. I think it’s a combination of fatigue from the first 4+ weeks and increasing FTP. I’ve learned that I need the mid plan recovery week to be even less TSS to properly recover. Don’t be afraid to lower Wednesday’s z2 ride and reduce the weekend rides if you’re too fatigued. Look at the Tips for each week in the GB MV plan.
Also, you seem to be all over the place with workout versus rest and recovery days. Looks like more is going on than just simply following the GB plan.