I would recommend getting copies of the following books:
• DeGowin & DeGowin diagnostic examination (shows you how to do many diagnostic tests and their findings as well as a list/glossary of pathologies and diseases). This is an excellent book for getting GP-style knowledge. They've been writing these since the 60s so if you can't pirate one you don't need to blow a bunch of money on a new edition, though I'd at least try and get one that's been published after AIDS was discovered.
• Physicians Desk Reference (comprehensive encyclopedia of just about every medication, down to what the actual pills and ampules look like), very useful even for the layperson, and almost certainly available for online piracy (it's big with drug users).
• Some sort of anatomy book as previously mentioned. You can almost certainly find an old Gray's Anatomy for cheap somewhere, and it's got a lot of helpful annotations, but there might be others you like better; I think the illustrations in Gray's are a little old-timey and harder to read. I have one I really like, but unfortunately I left it at my parents' house and can't recall the author. Shop around.
• Read through issues of the New England Journal of Medicine. I have no idea what it's like torrenting these, but if you can't find them online, university libraries usually have archives. These have the latest findings in medical research, interesting clinical case reports, and all kinds of miscellaneous articles. I think some of them have quizzes for continuing medical education, but that might just be for subscribers. You can learn a lot with an issue of NEJM in one hand and a laptop in the other, looking up terms you don't know as you go.
I can't tell you enough to remember to make use of your local library! Just because you can't torrent a book doesn't mean you can't find it for free.
You also might find it enlightening to take an emergency medicine course of some kind. In addition to getting certified and having lifesaving skills, you learn quite a bit about the body and various injuries and ailments. A Wilderness First Responder (WFR) course takes about a week and costs $800-1000 and will give you a lot of practical knowledge, or you can really immerse yourself (and get an EMT-B certification) by taking an EMT class which takes a month and costs about the same (or can be up to $2000, depending on who's offering it). Not only will these give you lifesaving skills that may be useful in an emergency, they're also pretty fun and can give you a sense for the thought process of triage and medical problem-solving.