Concern) My shoulder doesn't lift well~

It wasn't like this from the beginning..ㅜ

Lately, I've been having a lot of difficulty lifting my arms.

I thought it was just a job-related illness because it involves using my arms a lot and lifting heavy things.

Even though I have quit my job and am resting...

My arm hurts..

It's becoming increasingly difficult to raise my arm...

It's not easy even when taking off clothes...

Is this frozen shoulder or something like that?

I do stretching whenever I have free time... What else should I do to make my arm hurt less...ㅠ