Amoxicillin with ibuprofen

Amoxicillin has no effect on viruses it is an antibacterial

Loved the story - but just as an aside, aspirin actually prevents liver damage. Acetameniphen (Tylenol) is what is traditionally known as dangerous for the liver, and non-aspirin NSAIDs such as ibuprofen have recently been linked to stroke/heart attack risk increase. lol I know this has nothing to do with erotica, and your story is fantastic - but if it were me writing this? (and I do write a ton - I'm actually a professional author), I would have had Jack (the athlete) share his prescription pain killers with his victim, since he's most likely on them (athletes are always getting hurt) and since opiate prescriptions, added Tylenol not withstanding, are the only things that don't increase the risk of liver damage and heart attack/stroke. Plus... let's be honest. They're also the only medications that actually work. And also - it's the very least Jack owes him. ;)

I like your story. Your caveat about discontinuities at the top was way too understated, they were jarring, but I get it. I've been there myself, but please remember to come back and clean up later, you're going to throw a lot of people off.
OK, big problem: Never, ever, ever take Advil and Tylenol together! Ever! Tylenol is Acetaminophen, it's a blood thinner. Advil is Ibuprofen, it's an anti-inflammatory that will also irritate your stomach lining. So between the two, you'll end up with a bleeding ulcer. I think the standard recommendation is to separate them by at least twelve hours, though I just stick to one. So unless you're TRYING to mess Hayley up even worse than she already is (bruised, battered, hung over), PLEASE stick to one or the other.
PS: Yes, this is a pet peeve. Yes, I've personally had a problem with both drugs. Google it if you don't believe me.

Medical stuff:
Fracture = broken. We have lots of terms to describe the fracture, but a fracture is a break.
People can walk on a broken ankle if they are tough enough to take the pain and the tibia is not where the fracture is.
She would have had an x-ray about a week after the surgery to confirm it was well healing.
Plaster? We more often use water activated fiberglass these days. Less heat as it cures, sets quicker.
Very likely she would have been put in a walking boot.
Advil = Motrin = ibuprofen. Each pill is 200mg, so three were a good choice, four a bit better. Redose after six hours if the pain has returned.

When you refer to lifelong I think some more explanation is due. Did you lack the sexual cravings that almost all adolescents have? Did you masturbate before having sexual contact with another person? Not intercourse per se, but kissing, fondling..etc? Have you ever experienced an orgasm, with or without a partner? Does your vagina lubricate when you are exposed to sexual situations? As far as males with low libidos, often that's a result of another underlying physical, or mental anomaly. Please don't scare people, exogenous testosterone creams carry little risk. Most that find themselves in need of these creams are not under forty years of age, and usually older than than that. While I wouldn't recommend them to anyone who has had prostate cancer the risk is minimal. Taking over the counter medications such as Advil, Motrin, which are both ibuprofen, can cause severe kidney damage in large amounts, yet are safe minus pre-existing kidney problems, when taken properly they provide effective and safe relief from pain. The same can be said for exogenous or injected testosterone and estrogen provided it is used correctly. HSDS can, and does come with life changing effects. It has the ability to prevent and kill marriages. So if pharmocological therapy can eliminate or reduce the aforementioned effects, it should be understood that it remains a viable and safe option in the treatment HSDS.