I Have Been Experienced A Lower Quality Of Erection Quality.

I have been experienced a lower quality of erection quality. There a multiple factors that I am curious about. I am well aware of the effects of porn on the mind and erection quality, so I have completely cut out porn of my life. I am very curious as to if daily marijuana use impacts erection quality? Also, I am able to achieve erections but they do not feel 100% rock hard. They reach full length but I am able top bend it backwards slightly, which indicates that it isn't rock hard. I am only seventeen years old and this is become a huge problem in my life. Could it possibly been a mental thing that I have convinced myself that I can not achieve full erections? I very rarely get morning wood but like I said I am able to achieve almost full erections when I wish. Lastly, I am able to achieve decent erections just by looking at a girl and thinking about her, but again the erections overtime are not 100% quality. What is the cause of this?