Hello Pine, How are you doing now? Are you still taking Valtrex? Has it helped at all? Hope you are doing well. I've been taking it for a month now, to treat EBV and HHV6. My reaction has been similar to yours - increased fatigue, increased resting heart rate (up to 95 bpm from 60), increased muscle fatigue, increased sensory overload and cognition problems. Went from sleeping my usual 12 hours out of 24 to sleeping 14-15 out of every 24, and still feel tired and 'out of it' when awake. Also had itchy red spots on my back, but they are clearing up now. I am taking 1 gram 3x per day. Maybe I'll try cutting back and see if it helps. Would love to hear more about your experience! Thanks.