How do i tell my parents that im 16 and have erectile dysfunction i thought it'd get better on its own but after 4 days nothing has changed i'm scared?

Don't worry: First, rather than use term erectile dysfunction, you should describe what's going on. Ed is the inability to get & stay erect enough for sexual relations. Is your relationship w/your parents open enough to explain to them that you've already been having sex and that for last 4 days you haven't been able to get it up? Instead, just ask for an appt w/your family doctor. Tell him/her what's going on.

Anxiety: More likely you have performance anxiety. Unless there is an actual physical issue, such as injury, the most likely issue is performance anxiety. At age 16, there should be no physiologic reason for erectile dysfunction. Relax and try not to worry about it--or talk to your doctor about the issue.