Do check out Jim Wendler's 5/3/1/ program. Wendler has lots of experience. He played D1 college football. He was an SEC Strength Coach. He trained at Westside with Louie Simmons. He squatted 1000 pounds. Then he worked with Dave Tate at EliteFitnessSystems for years. Now he's got his own gym, and he's trained 100's of people. 1000's have had success with his program. Professional strength coaches, who train athletes for a living are like "fuck it, I'll just have my athletes do 5/3/1."
The guy who invented Stronglifts was trained by nobody. He has trained nobody. He said himself, that he lifted weights for years, but has achieved nothing when it comes to training.
More specific to you;
When you do your 2 workouts, and work your physical job, what is the most sore? What limits you the most?
You can do short, easy, specific mini workouts, at home, to address your weakest areas. After 3-6 weeks of attacking whatever is holding you back, you should be ready for a third gym session. At first, it will be shorter and easier than your 2 "real" sessions. It will be specifically for whatever is weakest. After 3-6 weeks of that, you will be ready for 3 days in the gym.
If we can get you on track, as you get stronger, your job should get easier. You'll be more hoss, so the job will take less out of you. This will allow you to do more "mini workouts" which will make you better, which will make you stronger, which will make everything easier, which will allow you to train more,and on and on and on...
The first step is to make sure your gym sessions are productive. Then, we figure out what to work on to make you recover better, so you can be more ready for your next workout.
So, tell us what you do during your 2 workouts. Tell us what hurts the most. Tell us what you do at work that fucks you up the most. Then, we'll tell you how to improve your gym sessions, and what "extra" stuff to do other days.
Also, you better tell us what you're eating. If you're sore and tired, you need to eat differently, to give your body what it needs to feel good and energetic.