Kyh, I'm sorry you are here; midlife crisis is a tough situation for both MLCer and LBS. With the help and knowledge from this forum, I'm standing.
My Grandma passed away during Spring 2012, I did not know my husband is stepping into the tunnel until he had bomb dropped on Sep. 2014, he doesn't know he is having midlife crisis but he did told me before he moved out that after my grandma's funeral, he felt something 'strange' started in his head...
He had money spent, drinking a lot (he never like alcohol) had both EA and physical affair with young women... blamed me for everything. Spewing on me, throw his wedding ring to me and moved out last Spring.
I studied from several site/blog, death of friend, relatives could be the trigger the crisis.
You read the thread that Cadet gives you and you learn boundary setting and detachment. Stay strong!! take good care of your kid and yourself. Give her to God.
