Hi Sally, I'm so happy to hear that you've been sober for the last three weeks, congratulations. My thougts are to just keep doing what you've been doing, since it's been working so far.
In the OP rehab I attended I recall the same feelings of anxiety at getting a bit of sobriety of under my belt, almost like I was afraid to believe in it. I tried not to get caught up in my own head, and just enjoy my new sobriety and do whatever it took today to stay sober.
I hope you continue to grow in your sobriety to the point that you feel like it's not conditional upon anything, that you are a sober person, and that you will do whatever it takes to remain sober. And that what it takes for you to remain sober may change over time, staying flexible.
I know you can overcome this Sally, I believe in you.
Have a great sober weekend!
