The one thing we experienced with Diamox when we did a practice run of it two weeks prior was quite a bit of fatigue the next day. The day we tried it, we weren't very active, so perhaps that contributed to it but that's just speculating.
During the hike, we spent several nights (Outpost for two nights, Trail camp one night) to ensure we were acclimated but didn't experience the fatigue side effect. It was only about a day or so after being back home that we had a few days of feeling like a battery at 5%, then one magical morning we woke up and felt completely back to normal.
We too have previously fallen victim to sickness above 11,500 and this time we just made sure we were drinking plenty of fluids, got better sleep, and of course the Diamox. We never pushed ourselves hard physically while heading up, kept our heart rates around a relaxing 105-115bpm. Best of luck on your trip!
