This one was alright, although it seemed completely clear to me that she was simply delusional.
The protagonist's belief that men were poisoning women this way to keep them under men's heel was rather annoying. I mean, if female medication is based on rainforest discoveries, wouldn't men's medicine also come from there? Maybe I just travel in different circles, but the women I know are anything but meek. If anything, the men tend to be less determined than them. Maybe someone switched their pills? I don't know. Also, if the spiders REALLY robbed her of determination, there is no way she would get rid of them with self-surgery. It certainly takes massive amounts of determination to put a drill to one's own head, don't you think? I mean, it takes a lot of determination to listen to someone narrate fiction about putting a drill to one's own head, so the act itself would be exponentially more difficult. I mean, if a spider had the trait to drain determination, wouldn't the point be to use it as a self-defense mechanism by forcing the host to be unable to remove the parasite? That alone convinced me that she is simply insane. Perhaps if she at least had some justification to why she's able to be determined right now ( a change in medication or recently getting an electric jolt or something, anything), that would allow me to see it ambiguously.
And the ending of self-mutilation followed by the mutilation to make others like her has just been done so many times. not that it's a bad ending, or that it's out of character for this insane person, but it's just so easy to predict that.