My Carob fudge is to soft and sticky, what changes the consistancy, the ingredients or temperature or both?

Since you're making fudge, I would recommend using the whole milk. I'm no scientist, but I'll wager that the milk fat does help to thicken the fudge, since whole milk is just plain thicker than skim. I would also recommend that you cook the fudge until it begins to pull away from the sides of the pan and is visibly thick. If this happens at 130, great. If not, keep going. The visual cue can be as important as the given temperature.