I am a 26 year old male who has in the past few months developed an unusual problem. I can't seem to achieve an erection while standing. Lying on my back, no problem. I'm always waking up to an erection. However standing up is another question. Normally this wouldn't bother me, however it's effecting my sex life as when I stand up (to get a condom for example) my erection just dies. What could I be suffering from and what can I do to fix my problem?