Okay I was in your position before. I am sorry to tell you that you are not going to change him, you have never stood alone, you have not followed through on your threats so why would he change? He will never change. My ex is on his fourth wife! He hasn't changed one bit. My ex was selfish, controlling, jealous, demanding, insecure, mean, abusive and a horrible father. You need to get a backbone, stand tall, and take one step closer each day towards the door. Find a way out. Ask family for help or seek out support groups for single moms cause they will give you the answer to how to leave. You may love him, but there is no love lost with him. No one who loves you would treat you that way, no one! Your daughter is counting on you. He is jealous of your EX because he is offering you something he can't or won't. You are only temporary to him. He will keep you around unless someone else comes around that might make a suitable replacement. Men don't like change too much. I think he keeps you around just for that reason alone. Men who are insecure do that. I was with my EX 2 years too long. You are way too young to think about till death do us part with this guy. He only has a possession not an equal partner. Run don't walk. Your just allowing someone to treat you like ****, your just as guilty for letting them. Like Eleanor Roosevelt said. No one can make you feel inferior without your consent. Do not give consent anymore! Best of luck!
Where is your family in all this?
You have GOT to leave this guy, and as soon as possible. I know you think it's easier said than done, but believe me, if you put your mind to it and stand your ground, it's just as easily done. If you don't have a family or friend's place to go to, get to the nearest women and children's shelter.
Don't let him or his family intimidate you into believing that he's going to "get the baby." That's not going to happen the way you think. Trust me. What will happen, if they're not bluffing with you, is they'll go to court to file for paternity (which will make him pay child support if he doesn't already), and from there the courts will make visitation schedules for the two of you with the baby (and if the father is physically abusive and you have PROOF of that, he'll be appointed to supervised visitation). The courts don't usually give fathers of infants/toddlers overnights or long weekend visits until the child is over 4 years old. Not always, but usually. That'll be the extent of him "getting the baby," unless they prove you're an unfit mother (meaning you're a combination of a drug junkie, stripper, prostitute, child abusing felon--sounds like you're not). Most likely, you and he will be appointed to joint custody, and you will be appointed as the custodial parent.
So do yourself and your daughter the biggest favor you can right now and GET OUT of the home and away from him, today if possible. You need to protect yourself and your child. He may not be physically abusive, but mental abuse and isolation is just as harmful--it can make you depressed and suicidal and it can really screw up your child.
The first thing he's going to do is try to track you down. He will yell, scream, and swear at you and tell you how you just made all the wrong moves. Don't give in, ignore it. Then he's going to cry and give you the whole suicide line again. Don't believe it. He's not going to do it, he's bluffing (I've been through this, so I know). Besides, the truth is, it's HIS life, and he can do with it as he chooses. You are not in charge of his decisions (but he's going to try to twist it to make you feel like you literally hold his life in your hands). If he kills himself, you're not responsible for MAKING him do it. But the simple FACT is that he won't do it. He's bluffing. He wants to control you, the way you think, the way you feel, the way you live. It's all about control over your life and decisions, not his.
Be strong, and do not give in to all the attempts he's going to make to control you. He'll use every tactic he can think of, so be aware of falling into these traps: intimidation, threats (direct and implied), vengeance, guilt trips, sadness and distress, and even say he loves and cares about you and would do ANYTHING for you. Don't let any of it fool you, as that's exactly what he wants and expects from you (after all, that's what he's gotten away with for 4 years).
He's not going to change. You can't make him change (although he'd like you to think that only you can make him change, and if he doesn't, then you're not trying hard enough). The situation is going to get worse if you don't leave; you and your daughter will have no life, no friends, and no freedom.
If one of your main concerns is that your daughter won't have her daddy, let that concern go--leaving him does not mean that you are cutting him out of your daughter's life. Chances are, as I mentioned above, he will have visitation.
If you can't afford a lawyer for your representation, contact your local department of social services, and they'll appoint someone to you.
Just get out of that relationship as soon as you can.
Good gosh, you are in a really scary situation here. He's abusive...and so is his family. He controls everything you do...can you really live like this? Do you really want your daughter growing up in a household like this? What does she see from day to day? Daddy disrespecting mommy over and over again. She will grow up and be in the exact same situation. Would you tolerate a man treating her the way her father treats you? These are some things you really need to ask yourself. Just to let you know, dada is what most baby's first words are. It has nothing to do with whether daddy is spending time with her. I would be scared that he would do something to her if he gets frustrated with her crying. A strong indication that he has issues was that moment when he wouldn't let you leave and he threatened to kill himself. Standing there with a knife would make me head for the hills. Honey he's not going to get any better, it's just going to get worse. Soon, instead of verbal and mental abuse, it's going to turn physical. He has cut everyone out of your life, this is what abusers do. He wants you with no job, no friends so that he's secure knowing that you can't leave him. These are all red flags going up. You need to leave him and you need to do it without him knowing you are leaving. Are there any domestic violence support groups in your area? You can benefit from speaking to some women who have experienced what you are going through. I hope you make a good decision for both you and your daughter.