I was a very healthy sexual male until about a month ago, and began experiencing impotence and now just can't stay hard for long. My stool has changed more reddish, and not as solid, i got an std test, and some more blood work done, nothing was found yet. I'm tripping because i just met a new girl and she wants to have sex and i'm unable to, cialis didn't really work, i still lost my erection. What is going on with me.