Not Going to Pilates Classes

I have signed up for a 3-months membership of Pilates classes. This was a result of a Model I was running for awhile regarding what type of exercise I want to do (and doctor’s recommendation):

C = Doctor said I will benefit from Pilates for my core and posture
T = I want to be that kind of woman who does 2-3 Pilates classes per week and looks great
F = Motivated
A = Sign up for a 3-months membership, buy new active-wear, schedule classes for the month ahead, and book them in my calendar
R = I set myself up to be that woman

The issue is that I signed up already a month ago and haven’t attended any class so far. The studio has a 12-hour cancellation policy and all the classes I booked so far, I either cancelled ahead of time or as late as an hour before class. I am having a few Thoughts that are running for me before the scheduled class:

T = You’re not going to make it and will probably cancel last minute {Creates self-doubt ahead of time}
T = You look too heavy compared to the other slim girls in class {Creates shame}
T = You should probably schedule them for the afternoons {Creates overwhelm}
T = You should probably schedule them for the mornings {Creates overwhelm}
T = I don’t feel like it {Creates unmotivated}
T = I don’t wanna {Creates unmotivated}
T = It’s too hot {Creates unmotivated}

So, I understand that I have two options before each class:

I could either spend time coaching myself to want to go or I could not feel like going, and let the urge to quit be there while I go anyway.

So far, I was able to get as far as 20 minutes before the class, to put on my clothes for class, shoes, grab my mask, keys and jacket, and then right before I had to leave the apartment I gave in to the urge to quit and stayed home instead.

What would be my next step and why is my brain so resistant to going?