I am a 19 year old male could you help me with ed problem doc??

Not physical problem: At your age this is unlikely a physical problem to begin with. There is probably a psychological cause tied to this. Do you like/love the one you are with? Do you have performance anxiety? Are you attracted to the other sex? These are things to think about, and if it may be a good idea to talk to a therapist and figure out what may be contributing to your performance issues.