Losing erection with my wife

I am 22 years old and have been married for 6 months. Over the past year and a half I have been losing my erection right before intercourse. We do not have four play. I used be able to hold an erection for a very long time.I do find my wife very attractive so I don't know what it is. I am able to have a erection it's just right we're about to have sex it gies completely limp. My wife is starting to get more and more frustrated with each failed attempt. And each time it just makes me feel like less of a man. Please help, men and women both.
Thank you very much

[palpateit]

As you probably know, anxiety is a very common cause, but probably not with a wife. I'm posting this in case you are a regular porn user, as many young men today are suffering from porn-induced ED.

Here's a simple comparison test to check for porn-induced ED:
1. Masturbate to your favorite porn.
2. Try to masturbate using no porn and no fantasy - only sensations. Masturbate with same speed and pressure as you would during intercourse.

Compare one and two. How erect was your penis? How long did it take you to reach orgasm? What was your level of excitement? A healthy young man should have no trouble attaining a full erection and masturbating to orgasm without porn or fantasy.
1. If you have a strong erection on #1, but problems on #2, then you have porn-induced ED.
2. If #2 is strong and solid, but you have trouble with a real partner, then you have anxiety induced ED
3. If you have problems during both 1 & 2, you may have severe porn-induced ED, or an organic problem. When in doubt, see a good urologist.

The following 2 links are to Medhelp threads on porn-induced ED. Read the stories. If you want to know more locate my first 2 posts on the link #1

http://www.medhelp.org/posts/Mens-Health/22-with-porn-inducederectiledysfunction/show/469209?page=1

http://www.medhelp.org/posts/Mens-Health/Too-much-porn-masturbation-causeED/show/183203

On  GOOGLE VIDEO find  “Erectile Dysfunction And Porn” - watch the video series.

Here’s a Psychology Today article on it
Porn-Induced Sexual Dysfunction Is A Growing Problem
http://www.psychologytoday.com/blog/cupids-poisoned-arrow/201107/porn-induced-sexual-dysfunction-is-growing-problem