I would say that calling different attorneys offices and asking about paying for the divorce would be the first step, now, so that it would have influence in your next steps...such as starting a private savings account so that extra pennies can be funneled in to start an attorney fund.
I think that finding out what money you'll need to have avail. is good no matter what you decide. I don't have time to go research your situation so I'll just guess. If you work then start making sure you have ready money on hand where you can get to it night or day. Cash, maybe with a friend that you trust to not be temped by cash hidden in their undie drawer...lol. That way if you need to get out in the middle of the night you are not stranded until the bank opens and your purse with all your money cards and stuff is sitting on the coffee table at home.
Have a bag packed for each person at that friends house too. That way if you leave and have the clothes on your back that is easily remedied too. Be prepared for an emergency, have copies of shot records, birth certificates, etc...all in those bags too.
Announcing you are seeking divorce or leaving often has unexpected actions by those we are telling so that is why the advice for the extra precautions.
Otherwise, if all is well and things work out nothing is lost. You have a S. set of stuff that if a tornado hits your house or a fire, etc...you have a back up plan.
I hope life takes a turn to work out so that you can find happiness and peace. Whether with him or without him. It is miserable being unhappy every day at home, home should be the happiest place on earth.