T.T.
B....1st and foremost seek counsiling for both of you. You and your husband are going to need it even if you decide not to stay together and the marriage ends in divorce you will need to have the help and guidance. Check with your church or other family service in your area if it is not affordable to you. It will be worth ever dollar.
Now for the meantime just because you are seperating doesn't mean you don't have rights... Not sure of your situation but if you own a house together than you have every right to stay right in that house till you face a judge same as if you are leasing and both names are on the rental agreement. Especially if you are going to have primary custody of the babies. You may want to seek out legal aid in your area to see what exactly can be done. Since he is brining it to your attention that he wants you to make a plan what is his plans? how is he going to help you? Don't allow yourself to feel trapped. Be as proactive as you can. Find support whereever and from anyone you trust. If he kicks you out you have the right to go anywhere with your children that makes you safe. So if you have family go to them let them help you. He really can't tell you how many miles that you can move and where that has to be. Just make sure that you have legal info from your state. Each state is different.
You are total right about decision making. You both created the life of your children and the responsiblity to them is to act and work together in a civil manor. It won't be easy but everything must be talked about and ever detail worked out because your precious little one will be effected by any negativity.
I know you have no job and don't work or have a car. You are going to have to make some sacrifices for your children. If you have family friends that can help watch your children or start looking for childcare on a slide payment or that has funding from other sources goverment based like headstart. You may feel like you are abandoning them but actually you are giving the life they deserve.
B. I wish you strength in this matter and hope that you find peace in your life with your children. T.