Welcome Tufts..Glad you found us!
By no way is my next statement meaning to embarras you or make you feel bad.
I checked both your photos, and on the top I noticed the hairline gone in the front almost to your crown. The bottom pic I can see most of your crown,which means 50% of your hair is gone at this point. Time to shave!!
Your head shape is great, you will be able to get a awesome shave the first try. Just take your time the first couple of shaves to get the hang of the contour.
As I was told during my week of partial hair to no hair, I did the fast trim thing, your kinda getting to the creepy science teacher look. Check my colage in the before/after pics, I was beyond weird science!!
I think the biggest decision will be how you want your facial hair, whether to bring it to a thinner line, but please not like Daughtry...he looks freaky

... or grow it thicker. Keep it like you have it and make the decision after you shave, you'll understand after.
Its a hard decision to make until you do it, then you ask why you waited so long.... and it will always grow back, thats when the coin flips and you wish it wouldn't!!
And the scar... remember the bar fight when you took on 2 guys and one hit you with the chair