A greater than 40" chest circumference is not plus-sized, thank you very much, especially not for a "Busty Girl Problems" t-shirt.
I forget my chest measurement, actually, but I'm darn sure it's more than 40". My band size is 38" by itself.
Very tired of clothes that only come in waif, super-waif, and haven't eaten in two or three years sizes
(And no, I'm not that overweight; my body fat percentage is <35, but I'm a real apple shape and carry quite a lot of that on the chest. I also muscle up across the back and shoulders like a draft horse.)