What a dirt bag he is!
Please DO talk with your family. Who cares if they know the truth? You’re going to need a support network to help you get through this; especially when you have a new-born.
His dad is a complete chauvinistic looser! What an idiot! We live in the 21st century, not days of servitude and ‘the little woman!’ Now we ROAR! We speak out. We support each other 💕
Can you start a Go Fund Me page to raise money for the divorce?
Cut this dead weight out of your life. Start arming yourself with information, secure the evidence you have so you can show it to the court if needed, take ‘cash back/cash out’ every time you buy groceries, as he’s less likely to suspect a few extra dollars on the grocery receipt. Open a mail/post office box, your own individual bank account and go get legal advice. Claim child support and spousal support from him via the divorce court. Sell everything you can get your hands on -discretely-that he won’t miss-so you can raise cash. Old jewellery, extra bits of furniture in the garage, camping equipment etc. use the money to buy baby stuff so you have it ready. Stock up on diapers, formula etc on your grocery shopping. Stockpile, in case you run short of money in the future.
Find out what assets he has. Grab copies of as much documentation as you can-in case he starts hiding things later. Take all your documents to your parents: Passports, marriage certificate etc-anything he could destroy out of spite when the divorce starts.
Seek legal advice/get prepared/then file his cheatin ass to hell and back.