To young to have ED??

I'm 19 years old about to be 20 and I just recently been starting to have problems with either getting an erection or keeping it,and I don't want it to get worse. I get an erection and sometimes before I even get to penetrate it starts to go soft again. We used to have sex at least 2 times a day. What could be the causes of this PLEASE HELP!!!! Is it from smoking,stress,not excercising enough or what??? I am able to get an erection but sometimes not when I need one. This has happened to me at least 4 times with my girlfriend. I'm just scared I think I'm too young for ED??? RIGHT??

You can have ED just as soon as you have erections. I wouldn't worry too much about it while you're still pre-pubescent but at 19 it's certainly a legitimate problem. Smoking, excercise and diet are things that usually cause ED on a long term basis. Stress can be more immediate but there are dozens of other possible causes.
I'd talk to your doctor about this. At 19 you have every reason to expect that you can regain healthy function.

Yea I am going through alot of stress and then this is making me stress even more. And now my girlfriend thinks its her and that shes not turnin me on which she does but that is causing even more stress this is not good!!! ,but thank u for the advice Im gonna talk to my doctor about it. Cause I dont want this to ruin my relationship cause I am really in love with this girl I just don't know how to explain it to her.

Tell her it's not a lightswitch, that you don't control your erection, if anything it's the exact opposite. Tell her that there are a lot of factors that can cause problems with erection and none of them are obvious. Let her know how your treatment is going. If you love this girl you need to be very honest about this problem.

ED is not a joke. Thank God there a lot of medications on the market that are effective.

Thank you guys for your advices

I recently had a consultation and my doctor said I should try Cialis 10mg
I hope this will help