Overwhelm when trying to narrow down my niche.

I want to decide to narrow my niche from a general life coach to weight loss.
I designed a class called 8-weeks Mindfulness-Based Weight Loss, and I want to focus on my marketing. But it is excruciating.
It means to redesign my website and Facebook page. From life Coach to this class.
I make it mean that I will lose many clients (I don’t have any paying clients, though) and feel pain in my entire body and a sensation that it is impossible. You are going to die.
C Mindfulness-Based Weight Reduction Class
F Anxiety, overwhelm.
T People will make fun of you; nobody will sign up, don’t give up on being a life coach; you can be both.
A Procrastinate
R Nothing
Can I find a way to be both?
How to find a way to focus only on my class?