I’ve just finished a 12 week Mountainous Grand Fondo plan in preparation of my own Mt Sufferlandria: Liege-Bastogne-Liege
The plan is tough, during the hard weeks I had to prepare myself mentally for each session, starting the day before. During the sessions I gave myself a target: I picked an interval roughly 2/3 of the way and told myself that I could go to Level mode after that. Sometimes I did, most of the times it was only 1/3 left, so I may as well carry on.
Level mode is great to swap to: not only does it allow you to continue without encountering the ERG spiral of death, it also gives that slightly more realistic road feel to the workout.
You’ll be doing a HM in about 2 weeks time, if your numbers are indeed too high, it will show up.
Happy suffering, you’ve got this!