Life is a process, a journey, pain and doubt are good because they remind us that we are alive.
I have little advice other than what you are experiencing are blessings as opposed to curses, you need not act on them just acknowledge them.
Mid life crisis gives way to apathy and acceptance, resist both but reasonable at the same time. We share some doubts but are miles apart on others, neither means anything, it’s just the journey, they are all different yet all the same.
Here’s how I dealt with my mid life crisis, perhaps my experience can help. A few months ago I allowed myself to fall in love, tonight I had some friends over over and I uncorked a decade old margeaux, tomorrow I take on a few work related demons. That’s it, no big secret, no huge changes, just run at it with a full head of steam and whatever happens, happens. Don;t worry about changing the world, just worry about your world, and never fret about your children pulling away from you, they are supposed to do that at some point, it is the way of things.
I found my Tao Te Chi that I had misplaced during my move a year and a half ago, go buy one yourself, it helps to feel happy about the disorder of things, even if you are catholic, a little Taosim never hurts.