problems maintaining an erection

Hello.
I have problems maintaining an erection. I can't even put the condom on because i lose it. Sometimes i manage to have one(like in the morning) but not when i'm trying to have sex. I'm starting to get unconfortable when trying to have sex and not be able to and i kind of become worried when i see i can't maintain the erection(or just have a soft one) when trying to have sex.. I'm afraid i won't be able to have a normal sexual life.
I'm 22 years old and had suffered from a testicular ectopy and had one of my testicles surgically removed at about 13-14 years old. I haven't had sex before so it's the first time we're trying to have.
What can be the problem? Is it because of my condition? If so what can i do to be able to have a normal sex life.
Thanks.

[SixStringer]

The fact that you are having erections in the morning shows that your "plumbing" is working okay.  However, because sex is new to you, you no doubt have some psychological issues present, and this is only natural, but these thoughts are interfering with your plans.  These anxious feelings may or may not be strong, but are having their effect on your situation, as you go down this new avenue.  If you take your time and educate yourself in sexual matters, things will go smoothly eventually as you gain experience.   Also, having one testical is not a problem, as many men have just one and go on to father children and lead a very normal life, sexual or otherwise.  The one testical takes over all the functions of two.