Way to go on 3 days!!
Sleeping a lot is normal. I was exhausted the first couple of weeks and still sleep a bit more than normal I think. Sleep is good. It helps your body heal from all the damage you've done.
You might take a read through this link. It talks a bit about what we experience the first while after quitting and what we can do to make it easier. It helped me a ton to understand what I was going through. I took the advice about eating 3 meals and snacks in between seriously and it really helped me a lot.
Why We Don’t Get Better Immediately: Post-acute Withdrawal Syndrome (PAWS) | What...Me Sober?