A couple more pieces of advice from me:
* A midlife crisis has its own glacial pace. Be prepared to be upside down for a long time.
* Be prepared not to be the same person you were before. Be prepared to learn there is no turning back.
* If you're in a midlife crisis, your previous life was simply not good enough and reality has caught up to you. Go through the process, and you'll become a better person.
* Outsource your mental health during this phase to professionals. Not even your spouse might be able to accept what comes out of this reconfiguration of yours. You will probably need the help of someone that is not invested in your previous existence to hold you in this trying time.
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3 years in, it's getting better, I miss part of my previous life, but I know who I am now, how I operate, and I won't compromise to fit someone else's mould anymore. In your childhood you had no say in how you were grown and pieced together. You had to carry whatever they had built for you until you broke down. Now is your chance to start over and do a better job at it.
Good luck!