you're living at home and eating your mom's good cooking so odds are you're fairly young, right? (ah.. 18, I see now). your diet sounds relatively health. you're young and basically healthy.
the benedryl has helped the itching so that's probably an allergic reaction to something.. something you ate or something you've come in contact with. maybe a new laundry detergent or shampoo. could be anything.
so.. odds are there's nothing horribly wrong with you. there could be but it's unlikely. so.. stop trying to diagnose yourself, stop reading about illnesses on the internet, instead of worrying about the worst, just expect the best. relax. breathe. do some yoga.. or go for a walk. eat some soup.

and keep your doctor's appointment on friday. But.. don't worry yourself sicker in the meanwhile.
actually.. googling (apparantly it's contagious

) indicates itchy hands and feet can be a side-effect of zoloft and/or prozac.. so maybe it's a side-effect of other meds too. you taking any meds? also seems to be common in pregnancy but I'm guessing it's not that in your case

and the liver is the thing they monitor most closely when you're on accutane.. so if you're doing that or have done, perhaps that's what's making the liver look wonky?
anno