from your narrative, it doesn't sound like mid age crisis. mid age crisis usually is something to do with reevaluating your life choices and regret what you have done so far, hence divorce rates are high when you are having mid-age crisis

back to your question, it just that you are have anxiety and lack of sense of security. maybe it's the job you are doing or maybe it's something deeper than that, sometimes even childhood trauma can affect your adult life behaviour.

here are a few things that I did to improve my mental well being:
-have a grateful journal
-simply thinking instead of always have the negative self-talk
-be in touch with nature, go for a walk in the park during the weekends
-living in the present moment, don't think of past or future
-have quality sleep, sleep longer doesn't mean you sleep well (circadian rhythm)
-changed my diet to more natural food instead of ultra processed food
-find out more about psychology, habits, neuroscience and understand why we behave in certain ways and how to overcome it, read a lot

do PM me if you wish to explore together