Burnout in a nikkei company, can someone give me advice???

So before getting in to the details let me just give you my background so you can understand my situation better.
So I’m a mixed Japanese and was raised overseas for 20 years (btw I’m 25 atm) I came to Japan and studied at a Japanese university and got a job in a Japanese company this year.

So I was hired as a sales associate and the salary was meh but it was the average. They have minashi zangyo dai for 45 hours, which tbh at that time seemed not bad if it stayed within that time.

Since working for 4 months I realized so many things,

1. I’m not just a sales associate, I have to do production planning, reading research papers related to products so I can think of new ways to improve product (btw we have a R&D department) and XYZ. The work load piles up so much that I do zangyo for an average of 12 hours per day.
2. It’s a very conventional Japanese company so the speaking manner, rules everything is just so inefficient and soul sucking. The other day I had to create a post for LinkedIn notifying our followers that we will be having a booth at an exhibition and this post took almost a week to get approved….a WEEK for a LinkedIn post so you can guess how it is for an official document.
3. The office is dark af! Windows tinted so no sunlight gets into our office, so I don’t feel a reset whenever I go into the office, I feel like I never even left the damn place to begin with.
4. My colleagues work life balance scares me and tbh it affects me so much. Most of them are single and some do have families but still work till the last train. I have my managers sending mails to each other at 3 freaking AM (btw I’m included in everyone’s mail convo). I know I shouldn’t be bothered by other people’s work life balance but it affects me because everyone looks at me weird when I leave early and kind of feel like I’m attacked indirectly at meetings for doing so..

Okay I have more, but I feel like at this point I’m just ranting. But the reason why I’m writing this is because I’m drowning with doubts and questions.

The question I have is that I want to know whether this way of living/work place life is normal? I have nothing to compare with since I just started work.

Is it normal to work this long hours?
Is this even normal?? Like idk what is normal at a work place anymore??

I don’t want to lose my self here, it gets suffocating and tbh I can’t even label them black company because everyone is so nice to me and I feel like I have the potential to grow here…
Can someone please give me some sort of advice?

Also sorry for making this so long…I’ve been broken and burnt down for a couple of days and needed some sort of direction.