T and R conflict

It’s my understanding that our R line can only be things that we control…is it ever true that weight loss is out of our control?

Sometimes it seems that my Ts don’t create an R line that proves them right. For example…

C: weight
T: I can TOTALLY lose weight
F: empowered, excited
A: work the SO program/coaching/self coaching for months
R: don’t lose weight.

I know that I can still choose to believe that T…but it isn’t creating the result for me and my results aren’t convincing me on that thought. What do I do when my T and my R don’t match up? Just wait for them, knowing that they eventually will?