Worried about healthcare in Sweden

Hej! I am moving to Sweden next month and while I am excited to live there, I am getting some concerns regarding the healthcare facilities in Sweden. I am not worried about the expense of healthcare at all but I am worried about the waiting time for getting an appointment with a doctor.

Suppose I get an infection and I want to see a doctor, an appointment can take a long time during which the infection might increase. What do I do in such situations? Can I directly go to ER and get medication?

I heard that medicines cannot be obtained over the counter and requires doctor's prescription which can take time. So how can I get the needed medications?