Well, I'm sad
to hear it has come to this, but know that this has been brewing for quite awhile. I would advise you to go to see a lawyer who specializes in divorces as soon as possible. Once a couple decides to separate, it's important that money matters get settled immediately. Too often, one person will clean out the bank account and leave the other with nothing. It would be good to establish your own bank account that he will not have access to, so you can start putting away money for you and the baby.
Sit down and make a list of all that you will need to support yourself and your child...a dependable vehicle, health insurance, etc, and figure out the costs associated with each thing (like auto insurance for the car, etc). Your lawyer will need to know how much you need to live on for negotiations for child support.
When a woman finally makes the decision to leave, she will sometimes say "I don't want any help from him" because she is just tired of all the disagreements. I strongly suggest that you get good legal advice before making any such decisions. As a mother working full-time, you will eventually need to pay for child care, which is a huge expense. Talk to any friends you may have who have gone through the divorce process.
The best way to protect yourself is not to give up any of your rights to spousal support or child support during the first year, at least. You'll need time to see what your expenses really are going to be, now that you'll be on your own.
Also, protect yourself emotionally by staying out of discussions of the separation with his family. If they come at you with questions, just say something to the effect that's it's too personal and painful to talk about right now. Surround yourself with your friends and your family for support. His family will very likely have strong feelings and you don't need the added stress
while you are figuring things out.
So, even thought it's just a separation right now, go see a lawyer right away to make sure you don't make any mistakes that will cost you later.