So sorry for what ur going thru OP. I would reiterate what everyone else has said.
Don't unfriend him on Facebook. Change ur settings so that there r no notifications. Delete ur status. U don't need to say ur married or complicated or anything. Just leave that setting blank.
Move all his stuff into the spare room or annexe whichever is available at the moment.
Get all ur documents together. Get a new bank account in which u can transfer at least half the money after bills r covered.
Don't do anything for him. Basically he wants to have his cake and eat it because that's what everyone in the city does. He doesn't want to split up because he doesn't want to deal with the hassle. Not sure how old he is but let me tell u, a young girl in the city having an affair with an older man she knows to be married, is probably in it for everything she can get out of it so start protecting yourself and ur daughter from the chaos that his selfish behaviour r going to bring.
Get yourself a shit hot lawyer. I would hold off getting a job. He probably doesn't want to have to halve his assets so maybe a divorce petition might bring him to his senses. Or not, in which case free yourself so u can still find a way of enjoying ur life without this stupid man who has treated u more like a doormat. If he was unhappy he should have talked to u abt it rather than go shag some cheap bird in the city.
Get angry but focus that anger on getting all ur ducks in a row. Don't fight with him or waste ur energy on him. Give him the silent treatment. Show him how strong u r. Empower urself that's going to rattle him more.
Sending u a big virtual hug and wish u lots of strength. Go on that weekend away and spend lots of money on spa treatments and nice meal.
Tell everyone that he is having an affair and ur relationship is over. He doesn't want to deal with the reality of his actions. Make him face it whilst standing tall and dignified.