Unable to get an erection is frustrating

Patient: Hi, I’m 17 years old and recently I’ve had problems having an erection. I was unable to perform, but this had never happened before. I knw I’m too young to have ED and I don’t have any heart conditions. I was unable to perform, and three days have past, I have not attempted having sex but I can’t get an erection even with stimulation. What should I do?