Medical Question

I’m in highschool (16F) but this reddit is very active so I have to ask a question 😭

It’s Saturday currently almost Sunday, I’ve had a bad UTI since last Sunday. I’ve been trying my best to treat it with meds, juice, and water, and it’s not going away. My parents won’t take me to the doctor as they are too “busy” but my school nurses said I should bc it’s concerning I even have one if I’ve never had multiple. My parents think I’m fine, I’ve asked my sister to take me too and she won’t take me. I also have an infected burn on my ankle that the nurses also said I should get checked out. What do I do? Why do my parents just not care?