When did you get your energy back?

I’m currently 13 1/2 weeks pregnant and feeling so exhausted all the time from day to night I have since about 6 weeks. My manager at work has been very facilitating and has changed my working to 50% of my hours as he had caught me physically asleep on a number of occasions at my desk sat up 🙈 I remember my last pregnancy I had a lot more energy. The other day I was off work and I slept for a total off 16 hours and then went back to been after some food and snuggles with my LO my partner is being really supportive but I can see this is taking it’s toll on him too any advice or insight would be deeply appreciated.