Wanted to give you a pat on the back. 3 weeks is great. Once the physical withdrawal passes (and it probably has by now) allows the mental part to kick in and you have to stay vigilant. I am past two months and I find I have to daily keep focused on my goal of total recovery for a lifetime. The addiction brain does not give up easily and lies to us.
I'm praying for you and hope you keep posting since we all need to continue accountability and support. Our future depends on it. Stay strong and keep active.