Sluggish Transitioning From 6 Days/Wk to 3 Days/Wk

As I am starting a new job, I have transitioned from 6 days a week ( mostly OL style) triples etc to 3 days a week. I felt good doing 6 days a week (mostly lowish volume) and now I feel weak and slugish.
I had a good year last year where I gained 25kg on my deadlift. What makes for a better transtion and keeping the nervous system fresh?