Regardless of what you do, you're going to be exhausted. Your work/school schedule is too demanding, you're not getting enough sleep during the week to really recover, etc... There's just too many factors in your life. Things need to change, but it seems like a real personal thing that you can't really get advice from any of us on.
Maybe instead of a consistent workout routine, you should focus on a hardcore maintenance diet to try to keep off the fat until your schedule opens up a bit. The only reason I say this is because two days a week doesn't quite cut it. And if you're not home until 1100 PM, by the time you wind down and finally sleep, you're maybe getting what 5 hours of actual good sleep a night? That's pretty bad...
Like Red mentioned... Do anything possible on those two days I guess, but you'll be struggling a lot unless you change some other things...
'11 BMW E92 ///M3 - ZCP and DCT
'15 Ford F-250 - Lariat, 6.7 Powerstroke Turbo-diesel