I used to weigh almost 100 lbs, but all of a sudden I'm 88, I lost a cup size, and my shirts that used to be tight are now loose, along with a dress I wore in 8th grade, it falls right off me... (strapless)
Is it bad? Unhealthy?

How quickly did you lose the weight? And how tall are you? What has your diet been like? How much are you exercising?

Well through the beginning of September, I'm 5 feet tall, I used to eat suuuuper unhealthy, but I started eating healthier, but I don't think that's why... and I don't exercise...

That seems like a pretty short amount of time to lose that much weight. I'd call your doctor or a nutritionist so that you can discuss healthy diets and exercise.

Emm how old are you ? And are you sure you have been eating enough ?