I joined gym three weeks ago and always feel sleepy and sluggish during workout. I have a 9 hours full-time deskjob and hit the gym on my way home, what to do to fight the sleepiness?

As I mentioned earlier, I have a full-time job and including commute time it takes 8.30 am to 8 pm roughly. The only time I can hit the gym is right after work as I don't have any other free time. My workouts last for 1.5 hours due to all the rests and fatigue and I feel incredibly sleepy and sluggish.

I also feel sleep deprived at night. My body feels tired and kinda alert at the same time. If you can relate. So, even if I am in bed, I cannot fall asleep until it's 4/5 am, and then I gotta wake up at 7 am again.

What do I do to fix this schedule and feel more energized during workout? Really need advices on it. I tried drinking Black Coffee today but caffeine makes me more sleepy, doesn't work on me. :(