Sounds to me like you need to modify your plan. Get a job and then get out of there. You can always make more money - but, you may have to alter your current plans to fit the new situation.
In the mean time, avoid her as much as possible. Be nice, be helpful (make coffee in the morning, do the dishes, clean the bathroom, vacuum, etc.) AND be non-confrontational. It's really hard to not like someone who works so hard and is just plain "nice."
If she starts on one of her rants - politely excuse yourself and leave the area. Go to your room (if you have one), go for a walk - whatever to get away from her.
If she insists on discussing guns again, and you can't get out of the situation. Just say, "I'd rather not discuss that subject. It seems to upset you and I don't want to do that." Then change the conversation. If that doesn't work - then excuse yourself and leave the room.
Sooner or later, she'll figure out that she isn't getting anywhere with her rants because you refuse to participate.
If she ever wants to discuss it rationally - then do that and offer to take her shooting so that she'll have a better understanding of why you like to shoot - it's fun.
If she won't do that, then just tell her that you recognize that you both have opposite opinions and it would probably be better for both you to not discuss the subject because you can see how much stress that causes for her.
Attempting to engage in meaningful conversation with some people often isn't worth the investment in time.
One tactic you can use is to feign ignorance and make her explain everything. "Bang fetish?" "I have no idea what that is or what that means." "Can you explain that to me?"
As she attempts to explain things keep making her explain more and more...and when she gets really convoluted...just say..."Well, I'm afraid you've lost me."
If you can stand more of the farce...ask her to start over...always make sure you thoroughly question any and all logic disconnects by making her explain them.
At any point...you can use the bailout "I'm afraid you've lost me on that one...I just don't can't seem to follow your thinking..."
Then you can bail out by "having to do the dishes," 'have to take a shower," "have to wax my boots," "have to go to bathroom..." etc.
Approach it like Bruce Lee in "Enter the Dragon," It's the art of fighting without fighting."