Extreme exhaustion

I am 8 weeks out from an endo excision surgery and hysterectomy. I had stage 2 endo and adenomyosis. I kept my ovaries. I returned to work part time after 2 weeks and then slowly ramped up my hours to get back to normal hours. I am a biologist and spend part of my time in the office and part of the time doing fieldwork. I have been doing mostly office work since my surgery but this past week I did 3 days of fieldwork (the most I have done in a row to date since my surgery) and I feel absolutely wiped, like I could sleep all weekend. Have other people experienced this extreme exhaustion post surgery and when did things start to get better? Thanks in advance!