Trying to get it back

First off I want to say hello to everyone and that I'm new to this site. I have a few questions if someone could help me out here. I am in the Army and lifted religously on my last deployment to Syria|Welcome to GrowXXL, and managed to put on some serious muscle. Problem is, now that i'm back in the states and on Drill Sergeant status, I find my time to go to the gym severely limited. While deployed I was able to work 6 days a week in between missions. Now, I'm looking at 4 days max. I'm basically starting over, because I managed to loose most of the gains I made. I'm looking for some input on a serious plan for 4 days a week, something that will really put some size on me. As far as supplements: I'm taking BSN True mass, nitrix, cell mass, and Animal pack vitamines. Thanks for the help