Im 17 years old why am i having trouble keeping it up??

[BoBMalatoa]

Im 17 years old and i have a beautiful girlfriend that i love to death. we haven't had problems before with sex until recently. its happened the last 2 times we tried to have sex i just lost my hardon and the worst thing about it is that she thinks its her fault , yet shes so sexy and completely turns me on i dont understand!??!

[budsal]

If you haven't had this problem before and it just happened a couple of times, even in a row, you shouldn't sweat it.  you may be just nervous and nervousness will just make it worse.. try to calm down your nerves.  also it just happens sometimes, really for no reason.  Maybe you've been having alot of sex and your body is telling you to take a few days off.  really for 2 times don't sweat it .  if it keeps up for 2 weeks or 2 months, then worry, it likely won't though.  but what do I then know?  I'm just a carpet salesman with a small penis and his own set of problems along those lines.  And don't let her think it's her fault.  I'm sure sometimes she's very wet down there and ready for you and sometimes she's a little dry and perhaps needs some lubrication.  Same thing.  Don't worry dude be glad you have a beautiful girl who loves you and she should be similarly happy to have you.

Peace and happiness

[Psamathos]

This may have a variety of reasons of which some psychic and some physic. Has anything changed in the days before you found out about this problem? With anything I really mean anything. A change of diet, a row with you mother, anything that may directly or indirectly have an effect on your sexual performance? If so; fix it.

If not; it's probably something unnoticed, but it can't just happen from one day to the other.
However, you want a solution, not an explanation of the problem.I can't tell you what to do to get and keep a hard-on, but I will try.
The most important thing about a hard-on is comfort. To explain this I have to get a little complicated, but I think a bright 17yo can handle this.
All the stuff in you body that you can't control (heart rate, iris contraction, digestion etc) is controlled through you autonomous nervous system. This is comprised of two parts; Parasympathic and Orthosympathic. These are counterparts, yet both are always active, but in different situations one takes the upper hand over the other.

The parasympathic system is generally active during rest (sleep, break-time, eating). It stimulates a lower heart rate and digestion. This is logical because during rest your body needed (in the old days) to regain strength for the next hunt.

The orthosympathic system is generally active during activity (sports, cycling, sex). It stimulates the exact opposite of the above. During a hunt your body shouldn't waist energy on digesting your food, but rather on catching the pray.

Now, the erection is generated through the parasympathic system, so during rest, while the ejaculation is generated through the orthosympathic system. This is logical, when you're well-rested you will initiate sex, and in doing so, you will become active and ejaculate. In your case this might mean that you are so madly in love with this girl, your heart starts racing and you can't get an erection because your body is in survival-hunt-kill mode. Try relaxing with her first. Not even thinking of the hard sex you are going to have. Postpone the need for the erection. Make sure you are comfortable and relaxed (music kinda' helps).

For a better effect, you can try to have sex in the morning, when you both wake up (if you already sleep together). Your testosterone reaches it's daily peak at that point, and all power will be at the parasympathic part of you autonomous nerves.

Let me know if this helps you at all. I hope so, had the same problem myself..
oh and sorry for the long post, got a bit carried away at the science of it all there..