想要辞职口不难开

In this kind of situation, your resign is a good thing for your current boss.
He will fully understand your decision.

Just tell him: Thanks a lot for all your past in the past. I will never for get the nice time working with you.
In this kind of the economy, I believe your fully understood that I have to move on. Therefore, this will be my last week work at here. This Friday will be my last day.
I wish you all the best.

Thanks!