Give you some advice with someone who has been working in human resources for 10 years:

It is never too late. The key is to understand why you want to switch to be an English teacher in a training institution.

Is it because of your own interest, or do you like being a teacher, or do you think that teachers in training institutions have high salaries?

You have to think clearly about these purposes. Secondly, you can apply to several institutions first. During the interview, you can know whether your current level meets the requirements, and then if you really like it, you can strengthen the shortcomings. No problem, come on!