First lets clear up the viagra thing. Unfortunately we guys have seen this as THE wonder drug that will work for all of us and "make us the stud" we'd like to be. HOwever, viagra is only required for medical purposes when we simply can't get it up without some help. So, unless you have a prescription for it...I wouldn't be messing with it in the future. I'd suspect that you are focusing too much on it not working and that is causing the problem to be worse. You see, our two heads are VERY connected, once we have a problem like this....it's very easy to worry ourselves into more problems by focusing so much on the fact that the lil guy may not be ready to perform. It may be anxiety, it may be fear that you won't measure up and it may be that you're just nervous. However, I suspect that at 22 the problem is in your head, and not a physical thing. You masturbate right? You know that it works, right? So lets try not to worry about it when the time is right. I'd suggest focusing all your attention on her, make sure she gets everything she came for. Forget you even have a penis and just get into as much foreplay as you can. Its perfectly fine to give the lil guy a "hand" in the matter....or better yet ask her to...add masturbation to the foreplay. Once you've accomplished this then try for the penetration and I suspect that things will be just fine. Remember though that this is a common thing for us guys to deal with....happens to the best of us from time to time. No big deal, just laugh it off and move on. You may also try not to masturbate or anything for a few days or so before an opportunity. Hopefully this will help! Let us know how things turn out!