Model on raising my rates for my best client

As a freelancer, I have been wanting to raise my rates for my best client (1/3 of my revenue) for a while now. My thought was “They will not send me any more work. My new rates will be too high.” So I decided to do a model on it. Please let me know if I did it correctly. I put “Raising my rates” in the Action line and worked my way up from there.
C Working for X
T If they don’t send me any more assignments, I’ll have more time and be more motivated to look for new, better-paying customers wich exciting projects
F Relieved
A Raising my rates for client X
R No more work for client X (or a lot less work), so more time to look for other clients

This model really helped. I finally stopped second-guessing myself and sent the e-mail with my new rates. Just waiting for a reply now.