Thanks for using Health Care Magic Forum,
As you are just 21 years old there is no need to be panic,
ED and PE is common as you are in anxiety
itself does not lead to Erectyl Dysfn but Excessive Masturbation will tired your Penis and will not erect as before .
I advice you to Reduce Masturbation and increase ejaculation time by Relaxing and Breathing Exercise
Dont be in fear or nervous during / before sexual activity
Take Plenty of fluids and urinate before sexual intercourse.
I Hope I Provided Useful Information. Do ask Furthur Questions to help You get well soon.
Dr.J.Kingson John David