Why does my penis turn soft when im about to enter my gf

My penis is rock hard when i put the condom on, then when im about to stick it in her, it turns soft and it wont go in as easy.

answered similar question...my answer was best...here it is "Negative thoughts or worries can prevent an erection from occurring as surely as sexual thoughts or fantasies can produce one. A sign that your erection problem is psychological and not physical is if you can get an erection while sleeping, when waking up in the morning, or when masturbating, but you can't get one when you're with your partner. This can happen as a result of anxiety, stress, depression, conflict with your partner, or guilt.

Another common psychological factor that will sometimes keep a man from getting an erection is "performance anxiety." This happens when a man is so worried about getting an erection that his fear becomes self-fulfilling.

Before a doctor can decide how to treat your erection problem, he or she will need to know what's causing it. You may be able to help determine the nature of your problem by taking some of the following steps.

* Look for risk factors. Answer questions, such as: Are you taking medicine? Do you drink a lot? Have you suffered a groin injury? Are you depressed or under stress? Are you having trouble communicating with your partner?

* Make lifestyle changes. If you drink alcohol, cut back. If you smoke, get information on quitting.

If you use prescription drugs, ask your doctor or pharmacist if they could be interfering with your ability to get an erection. If you ride a bike frequently, go shopping for a wider, softer seat.