Do I Stay or Leave

I need some serious advice. I am struggling so  much mentally and I don't know what to do. I have been with my ADD partner for 4 1/2 years. We share 5 girls, 3 are his from a previous marriage and 2 are mine. We have a son who is 3 together. Since I have met him, my world has been turned upside down. I lost a home I built with my exH, went bankrupt, have moved 3 times due to not paying rent and being evicted, and now luckily have a VERY patient landlord or we would have been kicked out already each month we are behind on rent. I have a full-time job and make relatively good money. He has had odds and ends jobs, and is currently starting a new job today that he promises will bring in good money and we will no longer need to worry anymore. He has two court dates later this month, and faces a misdemeanor and felony charge. He was a salesman for a construction company. He is very good at manipulating and getting people to trust him. He got many people to give him money for work he promised to do and then never did it. He got me involved in a few of these lies. He talked me into writing bad checks to one of them and he would give me the money to put in my account, but never did. Talked me into lying for him telling them he was very ill, or had the materials in a location, but just couldn't get to them. Each time I thought this is the last time I'm bailing him out, but I wanted to help buy him some time to do the right thing. I had charges pressed against me once as his wife because he told the customers he and I were married. I also told another man I would take over his payments and since I was trying to pay all of our bills and didn't have any extra money, he also pressed charges against me, I never even met the guy.

Last July we became engaged, but since had to pawn my ring he got at the pawn shop to have some extra money. He is obsessed with his hobbies of fishing, golfing, playing baseball, and anything really other than spending time with his family. We have all of our girls together ages 10, 9, 8, 7, and 5 every other weekend. Every time we have them he tries to plan something to do and have his niece or dad come to our house to watch his kids. I have started trying to plan other activities with my two girls and our son so that I don't have to be responsible for all of the kids. The first 3 years, I would always give in and stay home most of the weekend to take care of them all. Since we don't have much money, I could  never take them to do things, so we would just stay home. After awhile of doing this, I just started getting tired of it. I feel bad because a lot of times his children are left behind to stay home, but I don't have a vehicle that can fit me and six kids, nor do I have the money to always pay for all of us.

We are always broke, he talks very mean to me when he gets upset. He has belittled me and attacked everything he knows I'm insecure about to break me down. When he is upset, anything goes, and he will say whatever he can to hurt me as much as he can.  After years of fighting like this, I have started to dish it back and say awful things to give him a taste of his medicine. Since I have started to do this, I have gotten beat up pretty bad by him once, and just recently he cracked at least one of my ribs. I know he is very insecure because I have never seen him naked ever, and he has never taken his shirt off infront of me. We have intercourse with lights off and usually he is never naked. We rarely have any foreplay, and when we do its because he is drunk.

He isn't very nice to my two girls. Says things to get to them, teases them non-stop, doesn't really talk to them unless he has something sarcastic to say or he is scolding them. He has rarely been there for me to pick them up or take them to a function if I'm in a bind. I have always had to get my ex or my mom to help me. I try to treat his kids as a step-mom, even though I'm not yet. I have taken them on dates to get clothes, out to eat, fun stuff. I often have to pick them up or take them places. I watch them quite often without him being around because he has things he wants to be doing. I talk to them about their lives and what is going on with them. I feel like they trust what I say more than their own father because they know I am going to be honest with them and stick to my word. Our kids have hear a lot of fights. A lot of mean things being said, a lot of swearing, normally on  his part. I try not to raise my voice and swear, but I know I have.

Our son has the worst habits ever and he is encouraged by his dad. He swears, every swear word there is, and he knows how to use it. I scold him, and his dad laughs at him. He says he loves him, and I know he does, but he isn't a "father." He doesnt care what he eats, if he is potty trained, what comes out of his mouth, etc. I feel like my fiance is our 7th child and I'm the only adult. I'm so frustrated, scared, hurt, unhappy, and depressed that I don't know what to do. We aren't married yet, but we share a son. I feel like almost every need I have is not being met as a partner, but I also know that I don't want to split up another child from a home with both mom and dad. I am basically the only one caring for our son. I get very little help. Having my kids only part of the time kills me. I hate watching their games and activities alone without having the other person that loves them as much as me by my side to experience it. Do I want to do that with my son too?? I don't know how to fix things anymore. I feel like I have so much anger and resentment that I can't even be close to as loving and patient as I once was. I have zero respect for my fiance because he has never provided for our family in 4+ years. He has done very wrong things to a lot of people, and hurt me in so many ways. How do I try and form a relationship when the other person chooses the wrong things time and time again?? Please help me.

Thank you!