Hydromaxm really weird. But also I don't think it has directly something to do with Penis Enlargement. You said that the docter couldn't find any damaged tissue's, and like, if no tissue is damaged or any other vein, then it must be something mental, like DLD said. You mensioned this pill you used for 2 weeks, that could lower your libido. Maybe that did something with your libido, because if i look at it now, i think you are not able to pump fully blood into your penis, and since nothing is really damaged in your penis, it is something mental.
And in your last post you say you achieve a 100 % erect penis, once in a month or so. That means that your penis is physical able to have a 100 % erect penis. So this states again that is has something do with mental or libido/hormones.