If anything, you can call the local abuse hotline in your area. They can refer you to the resources you need to make your plans and protect yourself. Get an attorney if you really feel he would have a chance at getting custody of your child (although, unless you leave the kid there with him when you leave, he probably wouldn't have a leg to stand on). If he has any police records, or convictions related to violence or alcohol/drug abuse, you can obtain these for proof of how unfit of a custodial parent he would be. The thing is, if you do this, you might have to do it all the way, and protect yourself by having info in hand that shows how messed up he is. Don't start feeling so sorry for him and his situation that you screw yourself and your kid in the process. If he has threatened you recently, or threatens you at all, get a restraining order. He might not do anything screwy, but the big red flag for you to go ahead and get out of the relationship could be that you really don't know what he is capable of. Not a good foundation for a relationship. Call the hotline, and maybe call your local Bar Assn. to see if you can get any legal help cheaply or for free, based on your circumstances. Don't worry about what his family thinks. I got berated by my ex MIL, who would call me at work yelling at me for what I did to her son. Later on, she was dying of Non- Hodgkin's and taking care of him herself (which he was all too glad to have her do). She got sick of it, changed her thinking, and actually apologized to me before she passed away. If his family thinks he's just fine, that's their own sickness/denial talking. You can't really worry about them, can you? Tell your family what is really going on. The more people who know the real story, the safer you are, and the more support you'll have. You do not have to protect him any more.
Your first step is getting support for yourself. Have people around you that you can talk to about this, and can give you real advice based on experience. If you are planning on just leaving him, and not telling him where you're going with your kid, you really need to have an attorney to advise you, and help you to legally protect yourself. Move to a secure apartment building that has either a security guard at the door, or requires someone to ring up to your apt before they can enter the bldg. And if he does appear at your door- no matter how nice he is playing, don't let him in. Meet with him only in public, or in the presence of your atty, if you feel he is capable of violence directed at you. Ask for supervised visitation only with your kid when it comes time to talk about custody. And get child support! He doesn't have to know where you live to pay it- it can be sent to the county atty's office, and then to you, or it can be garnished from his wages.
You have a lot to think about. Plan, plan, plan before you leave- if you don't feel in any immediate danger. But make sure he doesn't find out any of this. Don't talk to his family or friends about it, and don't leave evidence lying around for him to find. I would even watch how much you post about this online. He can get into your computer and find out everything you've been saying. Call the hotline soon, and ask them the best steps to make. And you can do all this and stay in school- I did. There are resources that can help you stay in school- I got a lot of help, because they knew I was willing to help myself in any way I could. And I made A's & B's, although I changed programs from RN to LPN, so I could make a living more quickly on my own.