PThe problem of my life

You could also say "My Life's Greatest Problem"

I started this job one year ago.

Past tense :)

It is a shift job, working inon a weekly basedis.

Not sure what you were trying to say here, so this could also be "It is a shift job, with a weekly roster" if that is closer to what you meant.

The morning and afternoon shift iss are excellent.

There are 2 shifts (morning and afternoon) so we need to use the plural here.

MThe morning shift finishes at 15:00.

There are so many thing you can do if your work finishes at such a time.

The above sounds a little formal, so if you want to be a bit more casual you can say "There are so many thing you can do if your work finishes at that time."

Especially, compared to the 9-5 working class, and not to mentionespecially those who regularly working late.

I think this is what you meant?

AThe afternoon shift starts at 15:00pm

That also means you have the whole morning to do thingswhatever you want.

Sounds a bit more natural this way. (What you wrote is grammatically correct, but sounds awkward.)

NThe night shift (23:00-07:00) is the problem!

Even if you have nothing to do induring the night shift.

This makes more sense if you join it with the next sentence to make "Even if you have nothing to do during the night shift, you will tried and exhausted."

You will become tried and exhausted.

Even if you have the whole day belongs to you, all you can do is just rest.