Please pardon my language for it is not my first .

Me and my wife married for 15 years, everyone around us thought we had a perfect married, with 2 beautiful kids . at first 3 years of married. she was pretty much have it all figure it out about her career, but i quit my first job because it require a lot of traveling. and so i was looking for something to do in the first 3 yrs, but no luck one after another failed. i have to admit it was my fault. but then my wife pregnant with our first child. so i decided to stay home as one person do this and the other person do that in the family to make it whole. or at least that's what i thought. well somehow she felt out of love (as she said) but every time we buy a house . because of me not working for a long time i didn't have my name on any bills or anything so my credit wasn't great. so she put her name on everything , she pretty much take care of everything financial. and i have to sign waivers to houses that we buy .
long story short. with her very high income. we never have problems but now she decided to cheat on me and i found out. she admitted to it and we're going thru divorce. here's the tricky part:
My son have medical problem and since he was born up to now i was the primary care and not only that but he's more used to me than her he sleeps with me and we have routine going that helping him not just at home but thru-out his school too.
now my wife wants to take 50/50 shared custody, but my concern is about my son with out me he will going into the agonizing phrase on his everyday life activities and learning abilities.
and on top of that my wife seems to think that for the past 15 years all of her assets are her's alone and it's all her doing. so because of the waivers i sign into the house. she pull all the money in banks we have and put it in the house as she said"i want to pay it faster" so now we divorcing and we have no assets to split that leaves me no money to take care of my kids. and without working for the past 15 years i am leaving high and dry. knowingly splitting 50/50 custody will put my son into that agonize state hurts me more than when i found out about my wife cheating .
only thing i see that's left in our financial is her 401k from her work. i don't have money to hire a lawyer to fight. and i don't want my kids to go thru the court fighting process.