I am Maturbating from my 7th standard(2007) till now college 2nd year(2014) by rubbing my excess skin of my penis by keeping between my two handstill now by the same method daily minimum 2 times. Now, From 2 weeks, My Penis is not getting erected much and I am not getting much sexual mood too and since i used to rub be excess skin like that, Till now it is as same like it is for kids. If I try to peel is by myself, It feels somewhat different so I myself stopping it. And I can't even change the way of doing masturbation like the normal upper and lower pulling the skin. Please Advise Me.