>i’m only eating all bran flakes, multi vita pill (only one) and sometimes i eat a protein Bar.
dude, you need a well rounded diet. if you don’t have fats to support hormone production, your libido/erection-quality is going to suffer.
have you considered dysmorphia or (if you’re actually measuring) how erect you’re able to get now as compared to the last time you measured? your penis might shrink a little, but that would only be due to reduced blood flow to the penis. if you’re noticing significant change and can rule these out, go to your GP.