How to get used to working 9-5?

I just started my first graduate role, and definitely need some tips on dealing with working 9-5.

I feel like going Uni was definitely a step back in terms of getting used to the real world. My course had no compulsory attendance, so I only went to the first lecture of every term. The remaining time was for me to go out, binge watch TV, play games and sleep (until like 1 month before the exam of course). I had no schedule and was free to do as I pleased.

I am finding it hard to get used to the transition. I am now all of a sudden in a situation where I wake up every day tired and dreading to work, by midday I start losing focus and at 4 p.m. I feel like I just mentally ran a marathon. By the time I get home, I am already too mentally and physically exhausted to deal with chores, cooking and personal finances.

Compared to my peers, I am definitely a lazy person. I like putting in the minimal amount of effort, and hate going "above and beyond". That is why, perhaps I find it difficult dealing with working 9-5 for the foreseeable future.

Any advice or help would be greatly appreciated!