I have this same problem and actually had it today. I work 12hr shifts 4-5 times a week and on my days off I watch my 6 month old all day, want to talk about tired. ..Im not a morning person so waking up at 5am and working out is out of the picture. To be completely honest bro, I have my best workouts when I push my lazy ass to get off of the couch and go. Im a night time gym guy, I get off at 7pm and go home and rest, then work out at 9-11pm. What helps me is watching you tube motivational videos or music. I dont want to be fat, I in vision my goals and say to myself " you aint gunna get there on the couch".

dont go to your house brother, go straight to the gym after work and shower there. youre already at the gym there is no backing down!!!!!!!!!!!!!!!!!!!!

Simply put bro... It's a state of mind! Sometimes you just have to grit your teeth and bare it..... Good luck! Disipline is key

When I was in the army working 12 hour days I would hit up the gym during my lunch break. I always just wanted to chill when I got off that's why lol

Early to bed, early to rise...
When I work out in the morning before going to work I actually have more energy during the day.

This is tangential to your issue - but don't forget to prioritize your workout and have a plan of attack for each day:

A.) Bare Minimum that needs to be done that day (squats, bench, deads, etc.) - think big movements here.
B.) Important Accessory work
C.) Nice to have's, but not the highest priority.

If you are beat to shit at the end of the day, muster all you can to get through A.
If you have the energy, go on to B.
And then if you can, on to C.

Some days, maybe you'll only do A, some days just A&B and other days you'll hit all three, but either way, that's ok...doing something is better than bagging the whole day - you're still making forward progress.

Build a gym in your house and don't sit down until you are done working out

I'm in the same boat. Everybody is different but if you could sleep afterword I would take a scoop of xplode. If I take a preworkout I won't sleep that night. Shower + Dinner + Couch = Sleep. I always eat vary light before I workout and then pig out afterword. It's a fine line because you want fuel but don't want to crash. Find a gym that's on your way home that helps.

http://www.vitalyte.com/

This stuff is high end we use it in the military as well as for professional fighting. You start drinking this it will make the difference I have no doubt.

When I was working construction I would eat slam preworkout and go didn't sit down because I knew I wouldn't get up. Sucks but I beat myself anyways because I knew I had to

Not sure what time you have to be there in the morning, but I have to work out in the early morning before work. At the end of the day, I have nothing left, and it compromises my workout. Foruntately my gym opens its doors at 5am. Not sure if this is possible for you, and it DOES take a little time to get used to, but it works for me. And I don't have quite as strenuous work as you.

what I do is when im at the time clock about to punch out and go home im eating. on my drive home in traffic im eating so when I get home I shower change. the least amount of time I spend home the better. mix a pre workout drink and drink it on the way to gym I also like to inject before the gym only cause it mentally gets me going good luck bro cant wait to hear some more answers