It is not a “crisis” if you find yourself in your 40’s or 50’s reevaluating your career or life choices– this is normal, and should be seen as an opportunity to make some improvements. Here is a recent article that explains this phenomenon:
Here is the link to an interview with a life coach that explains the importance of working with a guide through this process:
There are many great books out there that are also helpful, including The Road Less Traveled by Dr. Peck, and Butterflies are Free to Fly by Stephen Davis.
It is good to question. Enjoy the journey. Just know that all the answers you need are already within you.