I Obsessively Rub and Pick at My Scalp

I am 28 years old and I have been obsessively rubbing and picking my head for around 15 years. I have noticed that my hair line has moved back and that my hair overall has become thinner. No bald “spots” but an overall thinning. My question is if I stop now will my hairline return to normal and will my head become fuller again?

What you describe sounds a lot like trichotillomania, a psychological disorder of picking at the hair/scalp that often produces significant balding. In general, hair lost from this picking does not grow back due to years of trauma, as the impacted hair has been killed off.