i have been married for 5 months have not been able to consumate my marraige. i dnt get an erection

You don't mention whether you are a virgin going into the marriage, whether or not you did have sex before marriage and suddenly you are having problems, or whether or not you had sex in the past with other women so you have at least a comparison of experiences - or with this woman you waited till marriage and now can't get an erection.  The answers to these different questions would definitely help a doctor or health professional assess the situation and make recommendations.

Are you and your new wife engaging in foreplay or trying different settings, approaches to see if they help?  Are you waking up with full erections in the am?  Do you have any medical conditions or are you taking any medications that could be causing ED?  Again the answers to these questions would shed additional light on the situation.

I would seek help quickly since sexual intimacy is an important part of a marriage.  A urologist recommendation form your doctor (and your primary doctor's opinion) would be good starting points.