Unit low on Ammo question

[Falkenhayen]

As I'm about to take my 5th loss in a row all being "major defeats" my amatuerness in the CS is showing like a sore thumb. My immediate question is: I dont understand how and why units become "low on ammo"? and how do I solve this problem? because it's evident when attacking with unit who are "low on ammo", especially armor it seems nothing gets accomplished and is useless to even fire. I assume the HQ's need to be in the area, but it seems most of the time when I do bring the HQ's up closer to the battlefield I end up losing them, which as I've come to learn the hard way, are extremely high in VP's, not sure exactly why? Any thoughts guys? or does it have something to do totally aside from HQ's? Thanks

P.S. I'm specifically referring to "Test of Steel" over on the WF I'm playing as the French and taking a beating trying to assault a German area that is heavily fortified. I'm 2/3 in and still have a neagtive point value and I've taken two "25 point" hexes.

Thanks again Gentlemen,

-Gary aka Falkenhayen.