I feel like I've fallen for a freakin sociopath & I'm trapped bcause when I start to get over it, she starts..?

Obviously you're both looking at other people constantly, you said yourself you flirt with other people, she is going to get jealous, and no she isn't a sociopath, that's just your reasoning for her actions, she's just a jealous type of person, and she will protect her so called 'territory' i.e. you talking to someone she knows, especially when you're flirting with that person.