13 and half of my foreskin won't retract but half does, what do i do?

Hi Help,

You're NORMAL.  The foreskin separates from the glans and may not fully separate until age 16 or so.  It's the same with retracting your foreskin.  It may not fully retract until 16 or so too.

You can try to stretch the foreskin - don't force it though.  Get an erection and pull down on the shaft skin so the glans spreads the opening.