Hi Kooo,
This may not be my place, but just wanted to share a friendly reminder that your height/weight places you at the lower end of the healthy BMI range right now, which is great news! It could be the reason your body is resisting losing more weight- you're in a healthy place BMI-wise already
Rather than pushing your body to move into the underweight category (which is where 115 would put you), it may be trying to tell you to review whether or not trying to lose weight is best for your health.
I'm not telling you one way or another what is right for you, but I also noticed you're 16, which is an age when many of us chicks feel pressure to be thinner than what is healthy. I know when I was your age it was definitely a struggle to be bth healthy and confident in my own body at the same time.
Perhaps talking with a doctor, atheltic trainer, or other qualified professional for this tricky question would help you figure out the healthiest way to get to your body goals. Hugs, and good luck!