Same here. 42 first week. All the week muscle hurt. But have never been so highly motivated

I’m 54 so I understand how you’re feeling. The older I get the harder it is, but that’s why I’m doing it. Like Tje I feel highly motivated. 

Shawn, I have been doing CrossFit since 2007, and haven’t looked back.  Stay motivated and be consistent, you won’t regret the decision you made to start.  One piece of advice I can’t stress enough: make sure you really learn the correct technique for any exercise you do to the point it becomes automatic, especially lifts, before you make significant increases in weight or intensity.  Scale reps/loads and substitute movements as needed, quality is far more important than quantity.  Your back and other joints will thank you.  Again, welcome aboard and enjoy the benefits the hard work yields!