Every time I shave the hair keep growing down to my neck and I really hate that I'm 23 looking like 28 this ingrown hair and that's when the dark shade comes I'm light brown and its very noticeable major help please thank you

I don't have input on the ingrown hair, but as for the other issue:

Sorry, but you can't slow the growth. You're just one of those who get's the 5 o'clock shadow by Noonish.

Be warned, though: Shaving can stimulate growth, so if you start shaving more often, you may be making it grow even faster.

Try TendSkin it works wonders on ingrown hairs for men's shaving. You can find it anywhere online, be sure you are not allergic to aspirin.