How to tell the leader to resign is better?

The way to gently resign with the leader is as follows:

1, Teacher Zhang, I am very happy to work in our company for three months, which has made me gain a lot. Thank you for your trust and help. My colleague is also very good, but I'm sorry.

After working here for a period of time, I still feel that I can't keep up with the rhythm here and I don't adapt to the working environment here. I feel a little stressed. I want to change my working environment, so I'm resigning, and I hope my superiors will approve it.

I am not qualified for this job. Staying here will only bring losses to the company. Be sincere.