I agree with Trippin2.0 here. I think that the best course of action would be to leave her until she gets a grip on herself. Make her learn to respect you the hard way. Don't cave in to her guilt trips because you aren't a monster or selfish for taking care of yourself.

Once she realizes how hard life is without you especially if she is dependent on you financially and is on the streets homeless for awhile and she comes to you giving a sincere apology then welcome her back with open arms but state that if she continues her behavior next time you will leave for good.

Sometimes, the only way to teach somebody a valuable lesson in life is the hard way.