I'm at the end of my tether with my step-father

Echoing what elbows said. If you are at an Ivy League, you really have quite a few options available to you/

Also, I am not quite sure what your situation is – but I feel like at most Ivys I know of it’s strongly encouraged to live on-campus during the school year, and it should be possible to get a job during the summer and not do summer school. I’m a little confused as to your situation and why you appear to be living at home right now. Is it just a summer thing?

You could get legally emancipated from your family (I think olives is the person to ask about this?) at which point you could conceivably get very generous financial aid from an Ivy. A person I knew very well in college did something rather similar. It involved a lot of arguing with the financial aid people, and a lot of having to prove that he wasn’t trying to scam Free Money off of them, and I think he ended up with a fair number of loans, so you should definitely ask the appropriate authorities at your college before trying something like that. Still, if you want it badly enough, like my friend did, and ask enough people, a lot of things are possible.

As for your mother, she’s an adult. Her choices are her own, and you can’t make them for her. If she wants to leave him, then we can talk about what choices the two of you have, but it doesn’t sound like she does, at least from your OP.

If you aren’t maxing out your student loan allowance already, you can take out loan money to cover your housing and transportation, too (or go private, which I would recommend given your situation). I *strongly *recommend you live elsewhere, because even though the additional debt load will suck, isn’t mental peace and a stable home-life worth 10k a year?

You need to abandon any wishes of your mother getting out of there at present, and focus on maximizing your own happiness and survival. Once you’re out of college and land a decent job, THEN you can focus on moving your mother in with you (if she will even go). It sounds like she’s trapped in no small part because of her financial dependence on your stepdad. If that’s the only reason she puts up with his BS, then once you’re financially independent you will be able to help her get out (of course, if she’s codependent she may never leave, but you can’t address that until you have the means to do so).

At present, you need to focus on doing whatever it takes to get yourself financially independent. That means moving out ASAP (take out loans and live in a dorm or small apartment with roommates) and leaving your mother to reap the consequences of her own decisions. She’s not in any physical danger, from the way you describe their relationship. It’s sad, but she’s a grown-ass adult who is choosing not to help herself. You can’t help her yet, and trying to help her without the requisite means will only deplete your mental reserves and make it less likely that you’ll finish your degree. Don’t let her choices prevent you from making a good life for yourself.

Pretend your stepdad is a depressurizing airplane. You need to put on your own oxygen mask before you can help your mom with hers, you know?

Does the verbal abuse bother your mother? Or just you?
Has she asked you to step in?

I don’t get along with my mother’s bf, but I don’t have to she does. I have had my run-ins with him, he’s a control freak with a big mouth, but that concerns the two of us, not her. I don’t get into their affairs because my mother is an adult, capable of making her own decisions, and it would be totally disrespectful for me to tell her what to do, who to date, or what she should or shouldn’t put up with.
If he ever got physical that would be different, but for all his assholiness, he’s not abusive.
I’ve known women (and men) in what I would call verbally abusive relationships and the words just roll of their back. Your mother may just tune him out, accept that this is who he is and doesn’t take it personally, or may be calling him worse under her breath. She may do as my mother does and gives him hell later when nobody else is around to hear it.
You don’t have to like her choices in life, but you do have to respect them.
Quite simply, adults don’t tell other adults what to do.
Your shouting back won’t do anything to diffuse the situation, it won’t bother him, he may even enjoy it, and I hate to put it this way, your mother may actually enjoy having the two of you fight over her. Then again you may be stressing her out even more, or she may just tune out the whole bunch of you.
My mother’s previous bf was verbally abusive and one day I asked her how she could stand it and she said ‘huh?’ She wasn’t even paying attention to him

Do what you have to do for you, get your life together, finish school, and unless she asks for help, stay out of their relationship.
You can’t change people, but you can change how you react to them.
It’s a hard lesson but a necessary one.