I don't think the last two lines are didactic, Jen, but I think they're slightly inaccurate. Winter prunes (or some other word that means to cut in order to cure), spring heals. And I think you need a stronger word than painful. Excruciating is too strong. Something between those two. Aching, maybe. That's not right, though. Something about how you feel after surgery. Maybe drastic, which implies sacrificing something that's just before being vital, for the greater good.