How do I convince mom To leave my controlling dad

First off I have never EVER done anything like this but I am desperate.
My mom and dad have had problems all of my life and at times the emotional turmoil that dad puts my mom through really gets bad. I have watched him refuse to let her visit family and if she did it anyway there was heck to pay. He also has cheated on her on several occasions but because of me she stuck it out. I am old enough to know this isn't what I want for my mom she is miserable and cries a lot she tries to hid it but I know exactly when dad has put her through the ringer and I hate it I really hate it. She has hinted that she wants to leave my dad and to be honest I really wished she would and I have even told her so but she said she can leave me to deal with dad by my self... I don't want to leave home until I can make my own way and honestly me leaving and going with her would be more of a problem for her than anything else because dad would flip his lid and disown me for taking her side over his and if i don't go she won't leave and she will continue to be miserable...

She is stuck I am stuck and Dad gets to do what ever and say what ever to her and gets away with it and I feel like it is ALL my fault....

Help me get mom to see that I will be fine as long as I know she is ok and out of this mess.

Ask her to talk to her family members, a pastor or a priest or a Rabbi (whatever you religion is) or a counselor. I hate to tell you this but your mom is the only one who can make the decision to leave your dad.

Does he verbally or physically abuse her?

I know it has to be her choice but I feel that I am the reason she is putting herself through the mental and emotional and god knows what other abuse that dad puts her through they try to hide it from me but I KNOW whats going on I am not a kid anymore and I am just sick thinking I am the reason...

How old are you?

I am 18 and I know I will be leaving home someday when I get enough money saved up to get out on my own but I don't know how long that will take... I don't want my mom to suffer anymore because I cant afford to be on my own.

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I have tried to talk to dad but He blows up at me and turns on me and then her no matter what I do she suffers.

It's gotta be difficult for both of you. Has she tried talking to a lawyer to see what her options are?

If money is the issue, depending on the state where you are, your dad may still be obliged to support you specially if you are in school full time.

Does your mom work? How long have they been married?

I don't know if she has or not but I don't think so. She would be ok money wise she does work and so do I. I don't plan on going to college because I am just not cut out for that my grades were bad and I barely passed high school I would rather work and get job experience anyway.

They have been married for 31 years

So tell your mom you would go with her if she decides to leave your father. Maybe she worries leaving you with your dad.

I have asked her if I left would she and she just says she doesn't want me to leave because of her.... It's a no win!
I know she truly wants out I can see it and hear it but she is afraid of my dad for one thing.

Your mother IS getting something out of this, even if you can't figure out what it is. Try looking up "secondary gain".

I think you should focus on becoming a self-sufficient, independent adult, and let her worry about her relationship with her husband. She has been with him for 31 years; she knows what she has and isn't interested in changing it up.