Erectile dysfunction and weak penis.

I met with my partner more than ten times , I love here there is no problem in that I also perform four play but unable to get erection, I also regularly do exercises including an hour gym workout , breathing exercises and having protein rich diet (milk twice a day & protein) and having little bit of sleep problem ,sometimes wake up in night and having constipation problem "hard stools" in morning. As per doctors suggestion I tried to relax in front of partner, maintain calmness but when erection is not achieved throughout four plays,nervousness start to rise as it completely stops anything from happening. I am also having testosterone serum levels 875. So testosterones are enough. One more thing I continually masturbated in the past for almost 10 years regularly sometimes ones sometimes twice . Now I have controlled it to once a week . I watched almost millions of porn videos in that ten years . **kindly suggest me best treatment as per my symptoms** (home remedy& medicines)