Now I am working in a public institution and want to get a doctorate. Can I resign? I don't want to study on the job, or what should I do?
No, there are doctors who focus on short-term teaching. Although there is only a degree certificate at work, it is also very useful and better than your full-time job. Then you'll run out all over the street looking for a job. The most important thing for you is to keep your present job. It's too difficult to find a job now. You must think clearly.