Two-a-days can be helpful when trying to accumulate more volume but I think you should try some things before that:
Include one rest day/week
Include more modulation between days. You need some light days and some heavy days through the week. All you days have a pretty high load in them.
Include light recovery weeks every 2-3.
Reduce the intensity of some more of your aerobic workouts from Z2 down to Z1.
All the things you are saying indicate you are training close to your maximum sustainable load. Not allowing adequate recovery will eventually derail your progress.