What Causes Numbness On Penis?

Hey there doc! Im soon to be 21 and writing from Sweden, in hope to get the help I need. I ve been struggling these past 2 years with feeling the numbness and awkwardness on my penis and around it. It all started when I started smoking weed (i am clean now) with a couple of friends were I was getting extremely high to the point were I couldn t help myself. The friends I was around with was no good for me since one of them made me feel sick to my stomach and awkward all through my body. Then one day when we was smoking on a park, suddenly my penis just went hard.. I could feel it went hard but not that it was there (I know it sounds stupid) I had a little panic so I went home and checked it wondering what the heck was the going on, why is it like that? I never found out. It been like this for around 2 years now. And its really eating me up. I randomly get boners were I can t control it I can t feel like its there, and I feel how people look at me like it something wrong with this kid. I don t know if this is a mental illness because i ve been thinking way too much about how this one guy made me feel, but anyways I need help. I can t keep on living like this. I need it fast and I need it now! Please help me out doctor. I just want to be like I was before I started smoking weed again, and i ve been clean now since december.