I have a feeling in my penis, it feels like I am going to achieve an erection, but nothing happens. Could this be anything other than impotence.

See my comment. Your question is not clear.Do you have erections ever or not..If you are not able when you need to, there can be some help.It also depends on your medical history.Is your condition of recent origin? Think positively ! if you can afford it see a good urologist in your area.Good luck.
Could be. Some times extrem emotional stress can result in failure to archieve erection. If condition persist see a urologist.